"We're sisters. You're my family. What is you is me. There is nothing that you could ever say to make me let go. I love you."
-Blair to Serena, All About My Brother
Blair and Serena are the two central characters of both the Gossip Girl series of novels and the television adaptation. In both, the two often power struggle as they deal with growing up but maintain their relationship as best friends for life.
In the books, Blair and Serena are described as the two most beautiful girls on the Upper East Side. However, Serena seems to always end up the center of attention, something that bothers Blair to no end. Their central conflict surrounds their mutual interest in Nate Archibald, Blair's on and off again boyfriend; especially after it comes out that he cheated on Blair with Serena.
At the end of the series, Nate leaves to not be in between the two girls.
In Bad News Blair, Serena encourages Blair to model her mother, Eleanor Waldorf's, new clothing line. Blair is happy that Serena helped her get the spotlight and relies on her for help on doing well. However, Eleanor's colleague Laurel and the photographer, Terry, convince Eleanor that Serena is the better choice for the model; as she isn't as poised and uptight looking as Blair. On the day of the shoot, Eleanor tells Blair that they chose to go with a different model. Not knowing she was replaced by Serena, Blair goes to the shoot anyway and is hurt and angry when she realizes what happened. After a brief fight with Serena, she has a talk with Dan and realizes that it wasn't Serena's fault after all. They make up and steal Eleanor's clothing line clothes to have an impromptu photoshoot of their own. On Thanksgiving in Blair Waldorf Must Pie, the girls argue after Serena sees Blair kissing Chuck. When Blair later discovers that Eleanor disinvited her father, Harold Waldorf, from coming to dinner, she relapses into her bulimia. She calls Serena for help and they end up going out together, along with Dan and his sister, Jenny Humphrey.
After sleeping with both Nate and Chuck, Blair suspects she's pregnant. She asks Serena to pick up a pregnancy test for her, but remaining quiet when Gossip Girl posts a blast about it. After taking the test, Blair finds out she isn't pregnant and tries to focus on her rekindled relationship with Nate. However, Serena tells Dan about the whole situation; not knowing that Jenny is listening to the whole thing. Meanwhile, Chuck is angry that Blair isn't interested in him anymore and sends a tip to Gossip Girl that she slept with both him and Nate. After seeing the blast, Nate believes it's a lie until Jenny confirms the truth to him. Afterwards, Nate breaks up with Blair and reveals to her that Jenny told him. Blair realizes that Serena must have told her and confronts her about it. Serena denies doing so, but the two fight anyway. Later, Serena has a talk with Dan and realizes that Jenny most likely overheard on her own. At the same time, Blair is too embarrassed to stay in New York and plans to leave for France to live with her dad. Before she can leave, Serena tells her to stay and that they can ride out the scandal because they'll always have each other (A Thin Line Between Chuck and Nate).
After the return of Georgina Sparks to the Upper East Side, Serena is reminded of her party girl past and the real reason she left town. She later admits to Blair that she killed someone before going off to party to forget (All About My Brother). Blair finds her after searching all night and along with Nate and Chuck, is able to extort the whole truth from her. Knowing Georgina is the problem, they band together to take her down. In the season finale, Much 'I Do' About Nothing, Blair successfully banishes Georgina from town.
After being abandoned by Chuck in Tuscany, Blair returns to New York at the end of the summer to spend some time with Serena in the Hamptons. She brings along her new boyfriend, Lord Marcus Beaton, whom Serena isn't entirely convinced Blair actually likes. Blair admits she only started dating him to make Chuck jealous, but later changes her mind when she discovers he's really from a royal family. In The Ex-Files, everyone returns to school and Blair returns to being queen, despite Chuck reminding Serena that she was born to be queen. After breaking up with Dan and seeing him ask out another girl (Amanda Lasher) on their first day back, Serena decides to take over being queen as revenge, consequently dethroning Blair.
In The Serena Also Rises, Serena is forced to cancel watching Eleanor's Fashion Week show backstage with Blair when her mother, Lily van der Woodsen, accepts an invitation for her and her new friend, Poppy Lifton, to watch the show from front row. Hurt that Serena is abandoning their oldest tradition, Blair attempts to sabotage her at the show but fails. Also wanting to get revenge on Jenny for changing the seating chart she created for the show, Blair sends all the models home; hoping Eleanor will see Jenny as incompetent. However, Jenny has the idea to invite Serena, Poppy, and their socialite friends to walk in the show instead. Jealous, Blair sets Serena up to wear a dress designed by Jenny on the runway, hoping to cause controversy, but everyone, including Eleanor, embrace the mishap. Blair later tries to apologize to Serena, but she doesn't accept, as Poppy helped her realize that she shouldn't let her shine dimmer out of fear of hurting Blair. Soon after in New Haven Can Wait, Blair plans to head to her dream school, Yale University while Serena is off to Brown University. But after a showdown at school before departing, Serena decides to follow Blair to Yale and sabotage her. While waiting for an interview with Dean Berube, Blair overhears him laughing hard and having an an enjoyable conversation with whoever he is with. When she discovers it's Serena, she is shocked and as a result, bombs her own interview. Afterwards, Serena receives the last invitation to the Dean's private party, where he invites his favorite incoming students to win a chance for early admission by answering one question. She runs into Chuck, who gives her Blair's answer to the Dean's game question. Meanwhile, Blair bribes the Dean's secretary to get her an invitation. At the reception, Serena brags that she's stealing Blair's answer, but Blair isn't fazed. When Serena's name is called, Dean Berube reads aloud the name of the man Serena thought she killed, not the answer she submitted. Serena is left speechless but Blair fills in the details on who is he. The girls go outside and engage in a physical fight before deciding their friendship is over. The next day, both head to Dean Berube's office alone to take responsibility for the scene but realize the other was there too. They make up and decide to ride back to New York together.
When new Shakespeare teacher Rachel Carr begins teaching at Constance, Blair almost immediately finds fault with her while Serena likes her a lot. However, Serena begins to suspect Dan is cheating on her with Rachel and her suspicions are all but confirmed when she sees the two having a romantic dinner together. She takes a photo of the two and shows it to Blair, who was recently expelled after hazing Rachel and spreading false rumors about her sleeping with a student. Hoping to save her chances at Yale, Blair brings the photos to a parent meeting at Constance and Rachel is fired as a result (Carrnal Knowledge). Soon after, Constance puts on a production of The Age of Innocence, and Blair feels her life is finally perfect. However, her hopes are dashed when she learns Nelly Yuki received the only early acceptance spot to Yale. Headmistress Queller also reveals that Dean Berube informed her that after hearing of Blair's hazing of Rachel via an anonymous phone call, Yale will not ever accept her. Blair falsely accuses Nelly, Serena, and Dan of making the call and remains angry until she learns Rachel did it. Later that night, Serena tries to comfort her and apologizes for the comments she made while being accused, but Blair just asks to be alone (The Age of Dissonance).
In Southern Gentlemen Prefer Blondes, Serena confesses to her friends that her new boyfriend, Gabriel Edwards, used her in a ponzi scheme. Along with Blair, Nate, and Chuck, Serena attempt to incriminate him but instead learn Poppy was behind the whole thing. Meanwhile, Dan learns that his dad, Rufus Humphrey, invested his college money with Gabriel and tells Lily about the situation. Not wanting Serena to be involved, she has her arrested for theft while the group tries to trap Poppy into incriminating herself (The Wrath of Con). The next day, Dan bails Serena out of jail and escorts her to the prom, where Nate and Blair win Prom King and Queen. Despite their happy evening, they break up, as the realize their relationship belongs in high school. At the end of the night, Blair and Serena talk about everything and smile at the fact that they raised each other as they navigated their crazy world together (Valley Girls).
In the season finale, The Goodbye Gossip Girl, Blair gifts Serena with a framed photo of her mugshot and they hug before heading off on separate ways for the summer.
In The Freshmen, Serena confesses to Blair that she isn't ready to go to Brown yet and that she is staying in New York for awhile. Blair is comforted by this, especially after her first days at NYU leave her needing her best friend around.
In How to Succeed in Bassness, Blair tries to get Chuck to trust her again after a recent indiscretion but is hurt when he asks for Serena's help in planning a party but doesn't want hers. In return, Blair asks his uncle Jack Bass to send a liquor license to him but when Chuck discovers what she's done, banishes her from the party. Blair asks Serena to boycott with her, but Serena decides to side with Chuck. That night, Jacks sends Serena condolence flowers and a note, which reveals the license is a fake. She goes to the party anyway to warn Chuck, but learns that he already figured it out. They plan to use it to their advantage and call the police on their own party, knowing that the celebrities Serena brought, thanks to her new job with publicist KC, will get them lots of publicity. Their plan works but Serena is angry when she realizes Blair ruined the party despite knowing she was trying to prove herself to KC. The two begin fighting again and this carries into The Grandfather: Part II, when Serena points out that Blair is absolutely friendless at NYU. Wanting to prove her wrong, Blair hires a prostitute named Brandeis to pretend to be her friend at an election party for Nate's cousin, Tripp van der Bilt. However, Serena uncovers Brandeis' true profession and has her thrown out of the party. When Blair learns what she did, she informs Serena that she too is a prostitute, as she's dating a client of KC's and is being paid for it. Angry, Serena pushes Blair headfirst into a cake. In They Shoot Humphreys, Don't They?, Blair plans to skip Cotillion because Serena will be there but Chuck convinces her to go, saying she might apologize. When she arrives at a pre-ball dinner, she learns that Serena is Jenny's mentor but Blair insists she is the better choice. After they have an argument at the dinner, Jenny announces she doesn't need a mentor and fires Blair. At Cotillion, Chuck traps Serena and Blair in the elevator and informs them that they're staying in their until they make up. After awhile, they do and Serena admits that she went looking for her father over the summer but he didn't want to see her; and that she is falling for Tripp, even though he is married. Chuck lets them out eventually but Blair is annoyed when Serena decides to hang out with Tripp alone, despite her advice not to.When Serena's father, Dr. William van der Woodsen, returns to town, problems arise for everyone. Serena admits to Blair that her downstairs neighbor, Holland Kemble, revealed to her that she slept with Rufus, effectively meaning he cheated on Lily. However, Blair is suspicious of this story and her suspicions are confirmed when Nate, Dan, Chuck, and Jenny agree with her. They work together to figure out William's plan, which they do at a library benefit. However, Jenny has decided she wants her old family back and tips off William that everyone knows what he did. He takes the opportunity to try and flee with Serena, Lily, and Eric, but Blair, Dan, Nate, and Chuck are able to stop it from happening (Ex-Husbands and Wives). In the season finale, Last Tango, Then Paris, Blair invites Serena to spend all summer in Paris with her and the two leave together.
In Belles de Jour, Blair and Serena are revealed to have had an amazing summer in Paris. After being single all summer, Blair admits she just wants to go on one nice date before heading back to New York. While visiting a Monet painting, Blair meets Louis Grimaldi, who asks her out to dinner. Realizing he may potentially be royal, Blair accepts and invites Serena to come, as Louis is bringing his friend Jean Michele. At the dinner, Blair discovers that Jean Michele is really the royal one and Louis is just his driver. Disappointed that Serena has ended up with her dream date, Blair excuses herself to take a phone call from Eleanor; who informs her that Serena is also planning to attend Columbia University in the fall. Angry that Serena is trying to steal her spotlight again, Blair confronts her about it and pushes her in a fountain outside the restaurant. Once back inside, she learns that Louis pretended not to be royal to test Blair to make sure she wasn't using him for his title and she failed. Blair returns home to find Serena packing to go home early, but they talk everything out and Serena decides to stay the rest of the trip.
On the first day of school in The Undergraduates, Blair and Serena seek membership in Hamilton House, an exclusive secret society. When they arrive to collect their official member keys, Nate's new girlfriend, Juliet Sharp, admits the only key she has left is marked for Blair. Surprised by this, Serena doesn't deny Blair the chance to join and they make plans to have dinner later. However, Blair attends a small cocktail gathering for the house and accidentally stands Serena up. When Serena finds out what happened, she confronts Blair about it and comments that Juliet probably got in the way of her getting in. When she asks Juliet about it, Juliet lets it slip that Blair called to inform her about the Pete Fairman incident. However, Serena knows Blair would never pull something like that and they stage a fake catfight at Fashion's Night Out to corner Juliet into admitting she purposefully kept Serena out. As a result, Juliet is removed as keymaster for the house. Afterwards, Blair reveals to Serena that she had Dorota decorate a guest room for her at the Waldorf's so they can move in together as roommates. Serena happily accepts.
Later on, Blair decides she wants to become the face of Girls, Inc., a foundation run by Nate's mother Anne Archibald. She tells Serena, who encourages her to go for it. However, Juliet, Jenny, and Vanessa Abrams are able to successfully trick Blair into thinking Serena is trying to take the opportunity away from her. Angry that Serena would try to hurt her like that, Blair stops talking to her (The Witches of Bushwick). However, on Thanksgiving, Blair, Lily, Eric, and Rufus realize that Serena is missing but they soon learn that she was hospitalized on a drug overdose. Blair encourages Lily to have Serena sent to rehab to help her, noting that no matter how much they're fighting, she is terrified of losing her for good. Lily decides to have Serena sent to Ostroff, despite Serena's protestations that she didn't do drugs. After Dan breaks her out, Blair and Lily find them at the loft and Blair tries to convince her to get help, the way she helped her when she struggled with bulimia. When a Gossip Girl blast comes in showing a photo of Serena doing cocaine, she agrees to go back to Ostroff. Later that night, Jenny reveals to Blair that Juliet was behind the whole thing in an attempt to ruin Serena's life. Blair then teams up with Dan to get revenge and find the truth (Gaslit). After extensive research and a brief road trip to Cornwall, Connecticut, they find out that Juliet was looking to avenge her brother, Ben Donovan, who Lily falsely accused of statutorily raping Serena to get her back into Constance (The Townie).
In It-Girl Happened One Night, Blair is asked to do a profile of Chuck's new girlfriend, Raina Thorpe, on Valentine's Day. Knowing that seeing Chuck with someone new will only hurt Blair, Serena convinces Raina not to do the profile behind her back. When Blair finds out what she did, she sets up Serena to catch her new boyfriend, Ben, lying to her about his job. While Serena is angry at this at first, they make up at the end of the night. Meanwhile, Blair and Dan realize they might have feelings for each other and share a brief kiss to see what happens (Empire of the Son), and Vanessa later tells Serena about it.
When Louis comes to New York to see Blair, he tells her that he's there in secret so they must keep on the down low. However, his royal minder, Jean Claude finds out he is there anyway, and Blair convinces Dan to pretend to be her boyfriend so Louis can pretend he is only in town to attend the Pink Party. Dan skeptically agrees, but worries about hurting Serena when Blair proposes they share a kiss that only Jean Claude will see. Meanwhile, Serena is suspicious of Blair sneaking around with Dan and enlists her cousin, Charlie Rhodes, to flirt with Dan at the party to see if it makes Dan jealous. Charlie is also the one to later see Blair and Dan kiss, and sends a photo of it to Gossip Girl. While this photo convinces Jean Claude that Louis is not dating Blair, this causes problems to arise between Blair and Serena (Petty in Pink). Consequently, Serena informs Louis' mother, Sophie Grimaldi, that he is dating a commoner from New York, and supplies her with a book of Blair's wrongdoings via Gossip Girl blasts. Not pleased with Blair, Sophie forbids Louis from seeing her again and plans a party for him to meet suitable girls for him to become engaged to. However, Blair is able to talk her way into the party as one of Sophie's contenders. Despite her first initial good impressions, a drunken Chuck shows at the party in an attempt to get Blair back. After embarrassing himself and her, Blair leaves the party. At home, she informs Serena that she knows she is the one who sent Sophie the book but she figured it was payback for kissing Dan. Louis overhears a brief portion of their fight and later proposes to Blair, even though he knows he does not have his mother's approval (The Princesses and the Frog). At Blair and Louis' engagement party, Serena apologizes for what she did and admits that all she's ever wished for her was true love and happiness. Blair accepts and they make up (Shattered Bass).
In the season finale, The Wrong Goodbye, Blair and Serena hope to cross paths while Blair is in Monaco and Serena is in California.
In The Fasting and the Furious, Serena acts coldly toward Blair, as she's jealous that Blair is the star of Dan's recently released book, Inside. However, at the Waldorf's Passover Seder dinner, she apologizes to Blair for being rude and Blair accepts. Soon after, Serena plans a Breakfast at Tiffany's themed bridal shower for Blair, but asks the minions to deter her from the theme by pretending it's a cheap and boring party. Hurt that her friends don't care about her, Blair tells Louis that she wants to move to Monaco full-time to fully embrace the Grimaldi lifestyle. However, Blair is happily shocked when she arrives at the party and sees how truly her it really is. Meanwhile, Louis secretly releases Gossip Girl's sources via a list created by Nate for Serena in an attempt to show Blair how ruthless her friends really are. It comes out while the party is going on and when Blair discovers what happened, she blames Serena for posting git. Serena vehemently denies this and Blair believes her once Louis confesses he did it. Afterwards, the girls make up while eating cake (All the Pretty Sources).
After the car accident (Riding in Town Cars With Boys), Blair limits conversations with everyone, including Serena. When Chuck and Louis discover she's going on secret outings with Dan, they readily assume she's having an affair; an idea that Serena dismisses as ridiculous. At Nate's New Year's Eve party, she asks Blair what the truth is. Blair admits that she made a promise to God that she would go through with her vow to marry Louis if he saved Chuck's life, and Dan goes to church with her. Once Serena learns the whole story, she reveals to everyone that Blair has been covering for her new relationship with Dan and that they are not having an affair. Relived by this, Louis drops his accusations (The End of the Affair?). In G.G., Serena assures Blair that if she for any reason does not want to go through with her wedding, she'll run away with her. However, Blair chooses to marry Louis but the ceremony is interrupted when a video of her confessing her love to Chuck is released. Blair instantly blames Chuck, who denies sending it to Gossip Girl. Despite the scene, she and Louis end up marrying. At the reception, Louis informs her that he only went through with the wedding to save face and that he does not love her anymore. Hurt, Blair ditches the ceremony to escape to the Dominican Republic with Dan to secure a divorce without Louis' consent. Soon after she leaves, in The Backup Dan, Serena discovers she is missing and teams with Chuck to find her. After visiting the Waldorf penthouse, they learn from Dorota that Blair is planning to leave the country and is hiding out at an airport hotel until her flight leaves. They track her down, but are followed by Georgina, who catches the group in a photo together. Startled by this, Serena drops the camera that captured Blair's confession to Chuck and Blair realizes Serena sent the video in. After Sophie threatens to reinstate the dowry that will bankrupt her family, Blair unhappily agrees to continue the marriage charade with Louis. Later that night, Serena admits to Chuck that she took the camera to save him from being blamed, but Chuck says he didn't do it. Now knowing that neither of them sent the video in, they wonder who really did.
In Crazy Cupid Love, Blair returns from her honeymoon to Louis and decides to set up Serena and Dan on Valentine's Day to get back together. After being able to get them both to Nate's Valentine's party, she tells Dan that if he is as wonderful to Serena as he is to her, there is no reason she wouldn't want to be with him. However, Dan kisses Blair, as she is the one he wants to be with. Meanwhile, Georgina takes a photo of the two kissing and brings Serena in to witness it. Afterwards, Dan tells Blair that he felt her kiss him back but she says she can't act on her feelings because she would never hurt Serena like that. In Cross Rhodes, she plans to prove this to her by hanging out with Dan platonically all day. After seeing a photo of them together, Serena decides to go meet up with them. However, when she arrives, she sees Dan and Blair kissing again as they try to show what a true Dylan-Clair (their character counterparts in Inside) kiss would be. Hurt by this, Serena leaves as Blair chases after her. Outside, Serena demands that she admit she likes Dan, and Blair insists she would never hurt her and that she doesn't; but Serena argues that she can't watch Blair lie to herself. Later that night, Blair goes to the hospital to support Serena and the van der Woodsen's as her grandmother, CeCe Rhodes, is dying. She apologizes for denying her feelings for Dan and Serena accepts, saying she won't stand in the way of their being together (Cross Rhodes). After Serena is Gossip Girl for awhile, she finally fills Blair in on it. While Blair is initially surprised, she's more so because she could have helped her run the site. Meanwhile, Chuck is on the hunt for Jack, who holds the answer to who his father truly is. In order to help him, Blair asks Serena to pretend to be her at an interview she needs to attend with Dan to determine whether she can accompany him on his upcoming summer internship in Rome. Serena does so and they're accepted. However, things become uncertain after Blair finds herself unable to tell Dan she loves him and Gossip Girl takes her site back; and begins posting excerpts from Blair's diary that Serena left on the computer (The Fugitives).
In the season finale The Return of the Ring, Blair is beyond angry that Serena leaked the pages of her private diary. After Blair writes a fake entry about how Serena lied about reading The Beautiful and Damned to get her job on the film set, the girls engage in an explosive fight that ends with Blair kicking Serena out of her penthouse for good. Meanwhile, Dan sees an entry that is posted where Blair admits she is worried she will never love anyone as much as she loves Chuck and that her relationship with Dan is only intellectually stimulating. He gives her an ultimatum to meet him at the Sheperds' divorce party if she cares about him at all and Serena attempts to stop her from going to the event. When she learns Blair is indeed on her way to the party, she brings Dan into the bar and seduces him into sleeping with her while she records it. Afterwards, Dan realizes Serena manipulated him into cheating on Blair and leaves. Shortly after, Blair leaves for Paris with Eleanor and Serena begins using drugs again as she leaves the city.
After learning no one has heard from Serena all summer, Blair, Chuck, and Nate try to find her. Along with Dan and Georgina, they track her down at a house in Poughkeepsie pretending to be a Wisconsin bred girl named Sabrina. Blair attempts to apologize to her about their argument but Serena refuses to accept the apology, saying she is ready to move on without Blair as a friend (Gone Maybe Gone). Shortly after, Serena returns to Manhattan with her new boyfriend, Steven Spence, and scores the chance to host the Central Park Conservancy Gala. She agrees to allow Nate's paper, The New York Spectator, sponsor the event so long as he does not invite Blair. Meanwhile, Blair is shocked when Nelly is the Women's Wear Daily reporter sent to cover her new line. After a disastrous first meeting, Nelly tells her she has one more chance to showcase her collection alongside Poppy Lifton's. Blair sends her minions to collect surveillance on Poppy's line and they learn she is planning on having it photographed at the gala. Blair attends the gala but is found out by Serena, who says there was a reason she wasn't invited. She adds that she is just trying to move on with her life and has her thrown out (High Infidelity).
In Dirty Rotten Scandals, Blair is preparing for her first fashion show with the new line. Meanwhile, Serena is manipulated by Steven's teenage daughter, Sage Spence, into getting her a spot walking in Blair's show. When she approaches Blair about it, Blair agrees to let her in so long as Serena sits in the front row and will talk highly about the line to reporters. Before the show can begin, Serena gets offended when Blair seats Steven a few rows behind her to save room for press. She threatens to tell Nelly all her true opinions on the show, effectively throwing their deal out. During the show, Sage strips down to her underwear onstage, shocking the audience. Afterwards, everyone walks out and Serena and Blair each blame the other for the sabotage. However, Sage reveals she did it on her own and leaves with Steven. In Monstrous Ball, Sage discovers that Steven is planning on proposing to Serena and asks for Blair's help in stopping it. Blair agrees to do so in exchange for Sage wearing one of her dresses to Cotillion. In the first part of the plan, she calls Lily with concern over Serena getting engaged so young; which effectively works. In the meantime, Sage has her father take a ring gifted by her mother to be resized and has someone photograph him doing so. When Serena sees the photo on Gossip Girl, she realizes Lily must have said something to Steven to change his mind and confronts her at the ball. Lily admits that Blair called her with concerns too so Serena switches her blame to Blair instead. When she confronts her about it, Blair says she only did it to get her dress at Cotillion and that she would never try to ruin her proposal for real. Serena believes her and they reconcile for a moment before Serena goes to find Steven. Before she can, Sage airs the tape Serena took of her seducing Dan to everyone and Steven breaks up with Serena later that night.
After Serena and Dan get back together, they agree to make amends with everyone they've wronged. Serena begins with Blair, who isn't interested at first. However, she agrees to work with Serena when she offers to help get Sage's help in making her pop-up store a success. They set up Sage into thinking Serena is getting back together with Steven in the hopes of her coming to Blair to sabotage their relationship again. Their plan works until Sage realizes she was played and orders her friends to attend Blair's show but to talk badly about the clothes. However, the other girls fall in love with the line and ignore this plan. After seeing the store succeed, they make plans to have breakfast together the next day (Save the Last Chance). In The Revengers, Blair enlists Serena's help in taking down Bart Bass to avenge Chuck. Meanwhile, Serena is embarrassed by Dan's chapter on her and plans to secretly move to Los Angeles. She helps Blair as her one last mission in New York but Dan tells Blair about her plans to move. That night, Blair tries to convince her not to leave, reminding her of the time she almost did after her pregnancy scare. Serena hears her out but says she has no choice but to go somewhere to start over where no one knows her.
In the series finale New York, I Love You XOXO, Serena decides to stay in New York after Dan gives her his final chapter, where he reveals he was Gossip Girl all along. She attends Blair and Chuck's wedding and in 2017, Blair hosts Serena's wedding to Dan.
Serena: Look, Blair, I'm really trying to make an effort here. I thought everything was good between us.
Blair: It was. Before I found out you had sex with my boyfriend.
Serena: ...How'd you find out?
Blair: Nate told me. At least he felt he owed it to me to tell the truth.
Serena: I don't know what to say.
Blair: Don't bother saying anything. I wouldn't believe you anyway.
Serena: Blair, it was-
Blair: You know... I always knew you were a whore. I never took you for a liar, too.
Serena: Blair, how can I fix this?
Blair: You don't, Serena. You just stay away. From me, my boyfriend, and my friends. You're done here.
-The Wild Brunch (1x02)
Blair (reading her letter): "Dear Serena: My world is falling apart and you're the only one who would understand. My father left my father for a 31 year old model. A male model. I feel like screaming because I don't have anyone to talk to. You're gone, my dad's gone, Nate's acting weird... Where are you? Why don't you call? Why did you leave without saying goodbye? You're supposed to be my best friend. I miss you so much. Love, Blair."
-Poison Ivy (1x03)
Serena: Look, Blair, I encouraged you to do this. Why would I try to steal something from you that I pushed you to do?
Blair: BECAUSE YOU TAKE EVERYTHING FROM ME! NATE, MY MOM-
Blair: You can't even help it! It's who you are.
-Bad News Blair (1x04)
Blair: The rules are different for the Serena van der Woodsens of the world. People expect you to party, be wild, sleep with whoever you want, run away, come back.
Serena: Wait, are we really going back there?
Blair: You shot your reputation to hell a long time ago. It doesn't matter what you do, but I'm a Waldorf.
Serena: Well, since you and your reputation obviously don't need me and my low rent taste, you and the Waldorf name can weather this storm alone.
Blair: ...with pleasure.
Blair (to Serena): We're sisters. You're my family. What is you is me. There is nothing that you could ever say to make me let go. I love you.
-All About My Brother (1x16)
Serena: Well, I know you may find this hard to believe, but not everyone wants to go to Yale because not everyone wants to be Blair Waldorf.
Blair: Not everyone can be. Since we're not friends anymore, let me speak frankly. You're not that smart. You lack focus and discipline. Charm is all well and good but in the real world knowledge is power. You wouldn't make it past the first round of admissions at Yale no matter how hard you tried. Have fun at Providence. Oh, and maybe you can get your hair dreadlocked while you're there.
Blair (to Serena): I'm sick of always looking like Darth Vader next to Sunshine Barbie.
-New Haven Can Wait (2x06)
Serena: I always want to believe the best in you, Blair, but bottom line is, betrayal is in your nature.
-The Age of Dissonance (2x18)
Blair: Do you know how exhausting it's been being Blair Waldorf for the past eighteen years? All the work? The planning?
Serena: You mean the plotting?
Blair: Yes! Exactly. I'm glad it all blew up in my face. It was a wake-up call. I was such an overachiever I was headed for a quarter life crisis at 18.
Serena: Oh, B, you've had a couple of setbacks but there must still be a way to get into a great college and if anyone can do it, it's you.
-The Grandfather (2x19)
Blair: I can't believe I sold out Nate to be the next Jackie O.
Serena: Yeah, I always pictured you as the next Hillary.
-Seder Anything (2x21)
Serena (to Blair): You are high school to me. All of the boyfriends and mean girls and tests and teachers and our crazy mothers. We went through it together. We raised each other. You're my sister.
-Valley Girls (2x23)
Blair (to Serena): This night is finally over. And as far as I'm concerned, so are we.
-The Grandfather: Part II (3x08)
Serena: You don't need Chuck, anyone who meets you can see you're an elitist snob who is perfect to run a secret society.
-The Hurt Locket (3x13)
Blair: Serena! Come here. You've done some unforgivable things, like having sex with Nate when we were saving ourselves for each other or killing Pete Fairman, but how far is too far? Where is that place you can't come back from anymore?
-Inglourious Bassterds (3x17)
Serena: I just happen to have a thing for French waiters.
Blair: And bartenders and museum docents, anyone on a Vespa or bicycle, or wearing Zadig & Voltaire.
-Belles de Jour (4x01)
Blair: You are Serena van der Woodsen. We've been on campus, what, five minutes? I bet there's already an entire frat house filled with guys fighting over you.
-The Undergraduates (4x03)
Serena (to Blair): I'll stay away from Nate and Dan if you stay away from Chuck and Eva. No plotting, no meddling, no Blair Waldorfing.
-Touch of Eva (4x04)
Blair (to Serena): Have a little faith and if that doesn't work, a lot of mimosas.
-The Kids Are Not Alright (4x12)
Serena: You gonna be okay alone?
Blair: Not yet... But I need to start learning to be.
-It-Girl Happened One Night (4x15)
Serena: The only appeal Dan ever had to you is that he was mine.
Blair: You would see it that way. Because it's always about you, isn't it? I'm sorry to break it to you but Dan and I have a real connection. We did things like visit the DIA and debate Chabrol vs. Rohmer, things that we could never do with you.
Serena: Yeah, I'm sure you and Dan had a really deep connection. That is until a prince came along.
-Petty in Pink (4x19)
Serena: I have to say how lucky I am to have Blair Waldorf as my best friend. I may be the maid of honor, but the true honor is just knowing you, B. There is simply no one like her, no matter how hard some of you try. Congratulations to the beautiful bride. You have become the strong, confident princess I always knew you would. I love you so much, and I wish you and your prince nothing but happiness.
-All the Pretty Sources (5x08)
Serena (to Blair): They say people keep fighting about the same things until it tears them apart. You know what? Maybe we're there.
-Crazy Cupid Love (5x15)
Serena (about Blair kissing Dan): Oh, so that's your excuse? Multiple Personality Disorder? Or did an alien take over your body?
Blair: I would never do anything to hurt you.
Serena: Too late.
Blair: Look, it was a mistake, what do you want me to do? Self-flagellate? Wear a hair shirt?
Serena: If you're referring to the hideous fur vest you wore yesterday, I'm the only one who suffered because I had to look at it.
-Cross Rhodes (5x16)
Blair (to Serena): It is your destiny to be gossip worthy.
-It-Girl Interrupted (5x19)
Blair: Why didn't you tell me?
Serena: I don't know. I felt like it was something I had to keep secret from everyone, I mean, my best friend even. I know it was wrong and I'm so sorry.
Blair: I mean, I could have helped! Sealing fates, forging destinies, like an imperious Greek Goddess imposing her will on the guileless masses. But, I was wondering why Gossip Girl has being so nice to me lately. And a little off her game. No offense.
-The Fugitives (5x23)
Serena: Oh come on Blair, you're the one who can't move on. You're still in love with Chuck and you still won't admit it.
Blair: Get out. I mean it. I want you gone for good. Pack your things.
Serena: You can't hold me responsible for everything bad in your life.
Blair: I can because you are. The best time I ever had was when you were gone six years ago.
-The Return of the Ring (5x24)
Blair: So what you're saying is that you want to use me, your non family, to make a good impression on your new, real family.
-Dirty Rotten Scandals (6x03)
Blair (to Serena): I would never try to take away your happiness. At least not permanently.
-Monstrous Ball (6x05)
Blair (to Serena): This line was inspired by both of us, ruling Constance together. This is your success too.
-Save the Last Chance (6x07)
Blair (to Serena): But there's no Sara Beth's in LA. Or Serendipity. Or me.
-The Revengers (6x09)
Blair (on Dan's wrongdoings): Chuck is one of us. Whereas Dan, despite his years of trying, never will be.
Serena: What does "one of us" even mean after all this time? He's friends with our friends, we both dated him, his father married my mother, his new apartment is in my building..
Blair: S. We all hoped that Humble Humphrey would overcome his Brooklyn roots to join a higher social strata. I mean after all, it's the American Dream but in his case the dream has died.
Serena: Just give him one more chance. You don't know the whole story.
Blair: I know what I need to know. And that is: Serena van der Woodsen will never end up with a powerless striver.
-New York, I Love You XOXO (6x10)
- In high school they used to have croissants and cappuccinos while watching Breakfast at Tiffany's.
- When they were young, Harold used to take them to Yale for football games.
- They used to try on Eleanor's clothes, including her Manolo's, together.
- They were both on the field hockey team at Constance.
- Prior to their their summer in Paris, they had never traveled overseas together.