- “When I told my mom not to go away with Rufus, I told her it was because you and I were forever. I know I was right.”
- —Serena to Dan
In the novel series Dan and Serena date for the first couple of books but break up pretty quickly.
Dan and Serena have a on-and-off relationship through out the seasons. It is also shown that Dan and Serena love each other throughout the seasons.
In Pilot Dan has a long time crush on Serena ( since he was 15).Dan is one of the first people to see Serena back in person. He accidentally bumps into her, causing her to fall and spill the contents of her purse and leave behind her cellphone. In an attempt to see her again, he returns the phone to The New York Palace Hotel where she lives. He runs into Serena there and ends up on a date that with her so she does not have to go to the "Kiss On The Lips" party. They have a rocky first date, going to his dad's concert. The date is ended early because he gets a text from Jenny saying that she needs help at the party. Dan is highly embarrassed after this, as at the end of the date he only waves to her from a taxi. He and Serena end up going out again but he leaves her after Blair tells him about Serena losing her virginity to Nate.
At the Ivy Mixer, Blair tells the whole school and Ivy scouts that Serena is a patient at the Ostroff Centre, presumably for alcoholism. Serena then goes on stage and lies to protect the real patient at the Centre: her brother. Dan is surprised at Serena's apparent problem, especially after it seems that Serena has been making a real effort to change from her old partying ways. However, Jenny reveals that Eric is the actual patient, which then causes Dan to respect Serena for protecting her family. This event actually strengthens their relationship, instead of weakening it like Blair had intended it to do.
Dan's childhood best friend Vanessa, who is clearly jealous of Serena and very much in love with Dan. Dan is oblivious to this. Despite Dan's clear preference for Serena, Serena cannot help but feel jealous of how close Dan is with Vanessa, such as when Dan tells Vanessa that his mother came home, while Serena learns this from Vanessa instead of Dan himself.
Dan and Serena sleep together for a christmas presant.
When he learns from the Gossip Girl site that Serena was seen buying pregnancy tests he freaks out knowing that the child could very well be his as they've slept together. His father sees this as well and is extremely upset that his son may be a teenage father. Dan explains he will stay with Serena no matter what she does because he loves her. He tells this to Serena who says she's not having a child. Later on, he tells her that he loves her, and she responds with "Okay." which is not the response he was looking for. She later asks him why he loves her and he tells her a list he made of the reasons. She believes him and says she loves him as well, but she needs to help Blair. When he asks why, she says "one of the many reasons you love me." When Georgina Sparks arrives at the Upper East Side, intent on making Serena's life hell, she gets to know Dan behind Serena's back, pretending to be 'Sarah' and accidentally-on-purpose letting her dog run off its leash in the park, giving her an excuse to talk to Dan.
It is later seen that Dan and Vanessa have taken "Sarah" under their wing as they believe she is a new girl to the Upper East Side who doesn't know her way around.Eventually, Dan breaks up with Serena, because he believes that she has slept with someone else and he is tired of her holding secrets from him. A few hours after he breaks up with Serena, he kisses Georgina, believing that she is a helpless girl who is running away from a psychotic ex-boyfriend. Soon thereafter, Dan is convinced that Georgina is lying to him by being told the truth by Serena. He and Blair manage to fool Georgina into thinking that Dan would like to meet up with her. The real purpose of the plan, though, is to get Georgina to meet with her parents and then get sent to a reform school. Dan and Serena rekindle what is left of their relationship before Dan ultimately ends it entirely.
Season 2Dan occupied himself by having continuous dates throughout the summer, with Serena still on his mind. Upon being fired from his summer job, he heads to the Hamptons upon realizing that he has been missing Serena. He hopes that by seeing Serena he will realize that they made the right decision, and he can move on.
He arrives in the Hamptons, at the annual White Party, to find Serena and Nate Archibald in a passionate kiss. This reveals his true feelings for Serena as he shows obvious anger towards Serena's "cheating". Serena tries to convince him that she kissed Nate so as to make Nate's girlfriend (an older, married woman who was also paying him for being with her) jealous. Dan goes to leave, when he is confronted by a pair of girls he had dated throughout the summer. The girls, having found out about one another's relationships with Dan, pour their drinks on Dan and leave. Having been caught out by Serena for his hypocrisy, Dan and Serena retreat into the house to talk. They decide to meet up later at the beach, where they spend the night together.
The following morning, Serena and Dan decide to halt any discussions on their relationships until they are back in the city. After some confusion between who was to take the train and who was to take the bus, they both ended traveling back to the city on the bus. This creates tension between the two, and as Serena gets up to use the bus bathroom, she trips and falls on Dan. She pulls up Dan and the two go into the bathroom to "fool around". The two decide to keep their rekindled relationship a secret until they were sure of themselves. Back in the city at Blair's "Welcome Back" party, Nate discovers the two in an embrace, revealing publicly that their relationship is "back on".
In "The Dark Night" during the city-wide blackout, Dan and Serena talk about their problems while they were both trapped in an elevator. After a long talk (and a bit arguing), they realized they keep having the same fight, and break up.
During their return to school, Serena and Dan are now friends until he meets a transfer student named Amanda Lasher. They share the same interests and have perfect chemistry. Blair attempts to keep them separate by making her one of her entourage so that Serena wouldn't have to suffer seeing them together and so she also wouldn't have to lose the competition of rebounding. Serena meets Amanda and nearly makes a fool out of herself. Blair forces Amanda to join them for lunch. Dan, thinking that Serena is trying to keep him away from Amanda gets Serena, who was reasoning with Dan why it happened, irritated when he kept implying that she was the one who forced her to lunch. Dan and Amanda's relationship goes public much to Serena's irritation. Serena then invites Dan and Amanda to go out later that night which turns into as disaster as Dan and Amanda continue to make her feel out of place. Isabel and Penelope, after witnessing Dan go out with Amanda that led to the relationship getting public, offers Serena several suitors, one in particular is a Dalton lacrosse team captain. Serena's new suitor fails to impress Dan. Dan thinks that Serena used the lacrosse team to rub it into his face. Later on, Penelope ruins Amanda's hair with a little help from Chuck. Dan runs to Amanda's aid who brushes him off saying that she no longer wants to see him. Dan gets into an argument with Serena and leaves. The next day, he is shunned because of Serena's rise to Queen Bee status.
With Blair's situation with Chuck now out of hand, Serena gets Dan to help Blair and tells her that wearing him down would help her situation. Later on, he continues to help Blair by telling her that she should intercept him at home. With Blair desperate, he tells Blair that she should take a risk and say those '3 words, 8 letters' anyway. Serena confesses her feelings for Aaron and Dan gives her his blessing to date other people.
Aaron and Serena start to date each other while Dan realizes that he still has feelings for Serena. Aaron has been concerned that Serena leans emotionally more on Dan than him. He asks her to come with him to Buenos Aires for Christmas. Serena asks Dan for his opinion, and he tells her to go. At Eleanor's wedding however, Dan confronts Serena about his feelings for her. Because she knows about her mother and Rufus' relationship, and because she has already said yes to Aaron, Serena turns Dan down and goes ahead with Aaron's trip. Serena breaks up with Aaron during the holiday and Dan and Serena meet with each other and they both decide there are better off back together. Dan soon learns he shares a sibling brother with Serena and becomes ridden with guilt when Rufus asks him to let Lily tell Serena the news.
Serena and Dan attempt to return to normal, but find this difficult with Lily and Rufus, who have decided to go public with their relationship.
Serena and Dan's relationship hits another dead end when things become too much for them to take. First their parents start dating, then they find out they shared a half brother together, and now the mess of the rumor.
Season 3In Season 3, Dan and Serena don't have a proper relationship. In the last episode anyway, Dan wakes up with Serena in his bed. The viewers learn that the two did not sleep together but - after staying up until 4AM talking and drinking wine - they shared a kiss, that of which Serena classifies as them "falling into a comfortable path for one...or ten minutes". When Dan hears that Serena breaks up with Nate, he calls her, possibly to say he had feelings for her. When she announces she wont be back to talk to him till September he appears to be .....very disappointed. When he later learns that Serena is going to Paris with Blair, he goes online to book a ticket.
In belles de jour, Serena tries to avoid the inevitable decision about which of her two long-time beaus, Dan or Nate , she should return to.In Double Identity Dan is prepering him self for Serena's come back to New York.
In Touch of Eva, Dan is struggling with his feelings for Serena.
In Juliet doesnt live her anymore, Dan is still has these feelings for Serena then he admite to him, self that these feelings will never go away.
Serena returns from Paris and confronted with her old life she realises she has to choose. Whilst in Paris it is revealed she had to make her choice between Dan and Nate, in rehab she admits to Dan she had picked him.
When Dan later confronts Serena about it they both realise they have just one more chance to be together. They have already been together three times and they need to be sure the 4th time is right before getting together again. When Ben is released from prison, Dan helps him and Serena get together after realising he was wrong about his prejudices against him.In [[The Kids Stay in the Picture|The Kids Stay in the Picture]], Blair tells Dan that he has already found his Princess already - she then looks over at Serena who is further behind him - Dan looks to where Blair is glancing and on seeing Serena smiles.
Serena is mad at Dan when Charlie wears her dress and he doesnt remember Serena wore it at thier first black tie avent.
In episode 5 she tells Dan he is the love of her life but he doesn't reply. She soon loses Dan to Blair and is notable hurt by their flourishing relationship..
"I love you Dan Humphrey, Always Have, Always Will"
Serena : I would say I'm sorry about today, but in my head that just sounds inadequate.
Dan : Ah, you don't need to apologize. It's not your fault that I seem to drop everything just to make myself available to you.
Serena: I don't mean to take you for granted. It's just, if we're being completely honest...
Dan: We are.
Serena: I think that maybe sometimes I test you. You know, I keep thinking that if things get too hard you'll give up on me. But you never do.
Dan: And I never will. If you really need me, ever, I am there.
Dan and Blair (about Serena)
"When I told my mom not to go away with Rufus, I told her it was because you and I were forever. I know I was right."
- Serena to Dan
"Dan is my boyfriend. And I know we’re too young to talk about forever, but right now, that’s what it feels like."
"I know it does, sweetie, but–"
"But what? Tell me that Rufus is that important to you. Tell me that whatever the two of you have is the most important thing in your life, because that’s what Dan is to me, mom. The most important. I would rather be Chuck’s step-sister than Dan’s. Please don’t do this to me."
- - Serena and Lily
"Hey! What are you doing here?"
"I need to know why you love me."
"Because I do."
"I really want to trust you when you say those words, Dan, so maybe if I knew why, I’d stop being so scared of hearing them and afraid to say them."
"Okay. Well, if you want to talk about why…"
"It has to do with my mom and her many marriages."
"There. that’s why. Because I actually like it when you interrupt me, which is often, by the way. I love you because you make no apologies about being exactly who you are… Beautiful, smart, sexy as hell."
"Now you’re embarrassing me."
"That’s another reason. You’re completely unaware of your affect on me. You’re also completely unaware that you laugh like a 4 year old." (Serena laughs) "Just like that. And I love you because you can be with someone like me and still be best friends with someone like Blair. "
"Yeah, well, I tried to be."
"I know you do, and that’s not easy, but you never give up on her. That's how amazing you are."
"Well, you’re amazing, too, for being able to say all of those things, you just are." (they kiss) "And I love you… But I have to go."
"What? What–what is it this time?"
"One of the many reasons you love me!" (gives Dan a flying kiss)-Dan to Serena
Dan and Serena agreed that if they try their relationship its gonna be the last time.