Nate introduces himself to Aaron, who is of course entranced by his strange unworldly face and immediately relinquishes the information that Max is a dirty sister-fucker, and then they stop talking and walk away from each other. And scene! Nate runs off and Blair runs in, totally fucking freaking out. Serena spots her, gets scared, and rushes over immediately. Blair, who's barely standing at this point, tells her it was a disaster and tries to leave, but Serena wants to go with. How could she even tell this story? "No, it's fine. You stay. I just have to get out of here now." And scene! Blair runs off and Dan walks in; Serena grabs him and asks why B's so upset. And Dan does an unexpected thing, which is be awesome some more.
"Uh, yeah. Look... Look, Blair and Chuck were gonna self-destruct at some point, so I just... I may have helped it along." It's helpful to see the little ways he justifies this shit to himself, because normally at this point you just have him glaring hatefully at Serena and have to assume that he has reasons for whatever horrible thing he's just done. "Wait. You intentionally sabotaged Blair?" Dan teenage-boys that yes, but he didn't want to make Serena mad at him, and also they "completely" screwed over Vanessa, in a way he doesn't really know about, and which resulted in no net damage beyond the presumable accomplishing of her goal of saving the Brooklyn Inn sometime soon. Which hypocrisy on her disgusting part and which stupidity on Dan's part, Serena adeptly points out, are not even the point: "No. Whatever they did to Vanessa, that's different. This is about two people who love each other." Which you fucking know. You held her heart in your hands and you felt it beating so fast and you knew exactly what it was. Oh, Dan. "Blair and Chuck? Come on..." Serena's like, "Did you not want to spend the day helping Blair? Because that's what you did, and you were really sweet about it, and asked her the right questions and made her feel comfortable, and I could feel it across her shoulders when she was with you, and you were beautiful doing it, and in some ways I loved you more during that process than when we were dating, as did Jacob, so WTF."
Dan decides retroactively the following bullshit things, but impressively compounds their bullshit by saying them aloud: He only helped Blair for Serena, because she wanted it, because he doesn't care about Blair, because this is all meaningless anyway. All of which is untrue, and all of which he knows, but the thing is that Blair would kill for Serena, and he's been that way for Vanessa for a long time, and caught between three loyalties this is the only way he can rationalize any of it: by voiding whatever he did for Blair and why. "It's all a game to her!" Serena shakes her head; she was sure this time he got it. He did! "No, in this case, it's not. Blair loves Chuck. She's just been too scared to admit it."