Blair and Nate in "Remains of the J," from Season Two of Gossip Girl. This is the episode in which the outdoor kiss of them that's all over the Internet appears.
Serena: Blair will never forgive you for what you did to her. Chuck: Who told you that little piece of advice, your boyfriend Nate? Serena: Nate didn't say anything ... Chuck: Good. I don't think it's wise taking relationship advice from someone in a FAKE relationship. Call me crazy. (pause) Enjoy another night alone with your thoughts. Serena: Good luck on your suicide mission!
