This guy Louis walks up to Blair, who has framed herself this way every day in front of this painting, today wearing a beautiful orange number, and they flirt for a bit. He's very excited to find an American who loves Manet, because that is just so fucking rare. Blair bitches at him about assuming she's American and he points out that she still stupidly has her watch set to EST. Probably it just broke when Chuck fucked Jenny, like Miss Havisham. He asks her to dinner, which is technically what she said she wanted, and then his driver comes running up to call him a Grimaldi and take him to the embassy, which turns her around from just wanting like a nice date with -- to be fair, one of the hottest guys they've had on this show -- to wanting to be the next Princess Grace.
Serena's eighth boyfriend of the day is so not interested in letting her chat with B about her "real live prince" she just met, and all of her Monaco dreams that she is now filling up with bizarre yeasty craze. After some relatively adept GG wordplay ("Spotted: B&S, chic and cheerful up on Boulevard Haussmann. They dallied at department stores and stayed a while at Tally Weijl. Down on Rue Saint-Honor? They courted couture at Palais Royal and found the perfect outfits to ba&sh the competition..."), Blair sets to Googling her Grimaldi prince.
Serena is horrified, because for once one of Blair's weird nonstop fantasies actually came true -- a mystery hottie actually approached her, in the sad little tracks she was wearing into the rue from one tourist destination to the next -- and she's trying actively to ruin it through thinking. This is not the Serena Way. Blair finally agrees, and so Serena tries to change the subject to the course catalog that somehow founds its way, Hogwarts-esque, to their hotel.
Blair gets a text, interrupting: "I want to hear all about how Brown offers a major in raw foods, but..." Turns out it's a double-date, they're going to Baccarat, and his buddy Jean Michel is coming along. Serena -- note -- tries once again to recuse and defuse herself and the situation, pointing out that this is Blair's "princess moment" with the obvious unspoken corollary that Serena cannot help but outshine and ruin those, but B's not having it. She's got crown jewels in her mind. S puts off ruining both Blair's date and Blair's life for a little bit later in the evening, because she is a true friend.