Apropos of nothing, Blair strides up and starts screaming about "Enough with the blackmail!" and chasing away the young lady he was currently seducing. Slow as slow, Chuck takes off his sunglasses and looks at her like she's a crazy person, which is what she both is and is acting like. Her point is that she's doing her best to ignore Nate until Chuck calls off the attack -- which, as it would for B herself if she didn't have a hockey stick or implement of death handy, amounts to lying in wait, leering, and generally letting her drive herself crazy. He gives us the backstory that in fact the "avoiding" she's been doing is part of the blackmail: "I didn't say forever, just until the sight of the two of you together doesn't turn my stomach." She asks when that will be, and the entire viewing audience is like, "Never!" (Beat.) "Unless Nate gets naked again!"
Chuck encourages B to practice "patience and restraint," lest he come down on her like a sack of rapists, and she begs him to torture somebody else. He'll find somebody, but until that point -- about five seconds, I'm guessing -- she's the lucky winner of The Chuck Is Shadowing My Every Move Creepily Sweepstakes. I'd be creeped out, I guess, but the fact is that he's playing the Blair game really well, whether or not he's in love with her. She's a power player just like him, and vicious just like him, and he's probably playing this nicer than she would. Actually, she was way worse. Blackmail was like Day One back when it was Serena on whom she was constantly going apeshit: she hurt him, so she has to be broken, and once she says uncle, they can reevaluate. Given sufficient money, time and energy for drama, and no legal recourse, and we're all playing by Blair's rules anyway: he's admitting she's the one in control by playing this weak card, because it's the only card he has, and every shitty thing he does in this episode just exposes that weakness more and more. This kind of behavior would be totally gross if she was a delicate flower, or he had the upper hand, but in fact she is Blair: she's more man than he could ever be, and she's holding all the cards, so it's all actually like totally feminist. You say in the Metro Fourth Wave all the boys are turning into girls? No way, man. All the girls are turning into boys. And that is fantastic.
Serena strips down to a totally adorable black one-pieced...garment...you know I don't know clothes. It's like, black, with a big Kirsten Cohen industrial metal ring in the middle of it like J. Lo, and she looks totally hot. Chuck strolls up and offers to "turn that one-piece into a no-piece," and I'm fine admitting that, dressed as he is, as a landed gentry taking a bathing weekend to the coast after hunting on a safari, that it would be hard to say no. She tells him to find a "floatie" to bother. Where is Vanessa Abrams? He chuckles creepily and suggests that if Bart and Lily come back from South Africa tomorrow engaged, they'll be brother and sister. (So Anguilla was a lie, but then they went to South Africa. I bet Lily was totally like, "PSYCH!" and nobody ever heard her laughing about that.) "You know what they say -- the family that plays together stays together," he queasily intones, and Serena smiles about how now he's into incest, "the universal taboo." She imagines that it's one of the only ones that he hasn't violated -- and she doesn't even know what he got up to in Imaginary Monaco with Nate! Either way, I'm so sure, Chuck. Three episodes from now he's going to be like, "Actually, I was a virgin when I slept with Blair, and this has all been a madcap game of switcheroo, because I am the gayest gaywad that ever gayed." He offers to break one more rule with her, and she predictably is grossed out, but honestly I don't think she's buying it any more than we are. He leans in for a kiss and she smacks his drink into the pool.