Serena: Blair?
Blair: Serena, what are you doing here? It's late. Oh my God. What's happened? What's wrong? Talk to me.
Serena: I can't.
Blair: Of course you can.
Serena: No. No, B, this is the one thing I can't tell you. I can't tell anyone.
Blair: I'm not anyone, I'm me. You can tell me anything.
Serena: No I can't. Because then that would make you a part of it. And you can't be a part of this.
Blair: What are you talking about? You're starting to scare me. Hey, hey, hey. We're sisters. You're my family. What is you, is me. There's nothing you could ever say to make me let go. I love you. What is it?