Blair: "Dan, why won't you talk to me about my wedding dress?"
Dan: "The only thing I want to say about your wedding dress is that you shouldn't be getting married in it."
Blair: "Then go back to shutting up. I have crazy-as-shit reasons to do this, as you well know."
Dan: "Chuck and Louis think you are cheating on them. And you kind of are."
Blair: "Look. I love lying to everybody all the time. Why would you deny me that? Especially when I have entered realms of mental illness usually only trespassed by Chuck Bass on various rooftops?"
Dan, taking her hand: "You're right. We are best friends. I am slowly being drawn into your insanity."
They go into a brownstone together like they are fucking, and Chuck snaps pictures or whatever. He walks into the street without looking, and a taxi almost bumps into him going about twelve miles an hour, but then comes to a full and complete stop several yards away. Much like the fake cough of the Prince, it's so staged and lovingly dwelled upon that one must wonder why it happened. You won't have to wait long.
Serena & Nate: "[Endless blond chatter about events of our era.]"
Gossip Girl: "Hey, Nate. I thought you were a journalist with integrity!"
Gossip Girl: "The important thing is that the paparazzi didn't cause Blair and Chuck's accident. Look more into it. If shit weren't so boring right now I might tell you more or just say whether the fuck I'm saying, but first of all I don't roll like that and second of all, I have nothing else going on at all."
From outside their weird little private secret apartment, Dan calls Chuck to tell him there's nothing fishy going on. Chuck, who is standing literally three feet away, tells him to call off the dogs then. Dan nods -- well done, spymaster -- and goes back inside, while Chuck leisurely hangs out on the street corner to call the Prince of Monaco and tell him that Blair and Dan are doing who knows what and lying about it.
Serena: "Hey, Louis and Chuck! It's not notable that you two are hanging out together, especially without Blair."
Chuck, verbatim: "I came to tell Louis he was right. Blair is having an affair... With your ex! I'm referring to Dan, not the myriad of men since."