Kelly Rutherford (Lily) does not appear in this episode.

Dan: Hey! What are you doing here?
Serena: I need to know why you love me.
Dan: Because I do.
Serena: 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.
Dan: Okay. Well, if you want to talk about why --
Serena: It has to do with my mom and her many marriages.
Dan: 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.
Serena: Now you're embarrassing me.
Dan: 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)
Dan: Just like that. And I love you because you can be with someone like me and still be best friends with someone like Blair.
Serena: Yeah, well, I tried to be.
Dan: I know you do, and that's not easy, but you never give up on her. That is how amazing you are.
Serena: Well, you're amazing, too, for being able to say all of those things, you just are.
(they kiss)
Serena: And I love you, but I have to go.
Dan: What? What is it this time?
Serena: One of the many reasons you love me.

Blair: You're late.
Jenny: Yeah, I know. I had to drop some books off at the library. Sorry.
Blair: Would you do me a favor?
Jenny: Anything.
Blair: Move down a couple steps.
Jenny: You know, this whole hazing thing is getting a bit old, don't you think, B?
Blair: First of all, the hazing stops when I say it stops. And for future reference, only my friends call me B.

Serena: I'm not pregnant.
Kati: Aw, cool.
Iz: Congratulations.
Hazel: Celebratory drinks after school?
Serena: Sure, whatever.

Serena: I'm such an ass.
Eric: Let me guess, Dan?
Serena: He told me he loved me and all I did was stand there like a stupid mute. I mean, why wouldn't I want to hear those words come out of his mouth? But it's like it made me trust him less, which is crazy. And even if he is lying about telling Jenny, even though I told him I didn't tell anyone, I should have come up with a better response to "I love you."
Eric: Not that I even know what you're talking about, but why would you think he was lying?
Serena: Because I'm the only one who knows and he's the only one I told.
Eric: Do you know how many times I listened in on your conversations when you thought I wasn't?
Serena: None, I hope.
Eric: You hoped wrong. I'm a little brother, it's what I do. And you don't have to be a genius to figure out the trust thing. Every time mom brought home someone who said I love you, they would end up getting married.
Serena: And then divorced. Didn't leave us with a strong sense of trust, huh?
Eric: But that's mom's issues, not ours. And Dan's not like those other guys.
Serena: Okay, this conversation has to end because you're getting dangerously close to being smarter than I am.

Serena: Hi, Chuck.
Chuck: Please, call me brother.
Serena: I need to talk to you.
Chuck: About getting knocked up? I must say I was a little disappointed you weren't more careful.

Student: Hey, Mom.
Serena: Yes! I'm pregnant and it's yours!

Episode Title: The Thin Line Between Chuck and Nate

"The Thin Line Between Chuck and Nate" is a play on the 1996 movie, A Thin Line Between Love and Hate.