In the living room, after the ads, everyone sits around drinking wine, with Michael trying to act the oenophile with the use of the term "oaky afterbirth." Jan jumps up and puts on a record of her ex-assistant Hunter's band (which is horrible), getting way too into it and doing the embarrassing middle-aged white woman dance. Michael complains about Hunter (since fired by Ryan), which leads to complaining about Pam (Angela joining in and everything). Pam, in turn, whispering-heads from the bathroom that she just wants to eat. "Which I realize is a lot to ask.. From a dinner party."
Now everyone's playing Celebrity, and Jan and Michael have started sniping at each other more openly. So Jim decides to "make a run for it." He comes out of the bathroom, holding up his cell phone and claiming to have a text from his landlord saying his apartment is flooded. He says he and Pam should go, but when Michael tells Pam to stay, Jim's about ready to head out alone and leave her to her fate. Pam, the only one who knows Jim's full of shit, uses code to say he's not going anywhere, and indeed he isn't. Nice try, Halpert.
Back to Celebrity. It's still Michael's turn, and he's sucking at it. Jan's criticizing him, Jim isn't helping with his deliberately wrong guesses, and he runs out of time. You won't believe this, but Michael's a total spaz about it.
It's now the silent part of the party. Pam seems chilly, so Michael gives Pam his jacket. Seeing this, Jan decides to get her revenge by telling everyone the story of how the sliding glass door broke: Michael ran through it because he thought he heard the ice cream truck. "So I like ice cream! Sue me!" Michael snipes back, and then jokes meanly that he shouldn't say that to Jan. That was actually kind of a good one. He adds that the glass was really clean, and Jan, symbolically sharing the frame with the fireplace, says that she guesses having cleaned it makes her the Devil. Michael raucously agrees, laughing, "And I'm in Hell! I'm burning!" This is what you call kidding on the square. Pam wants to escape to the kitchen for more wine, but Jan decides it's going to be a "girls' trip," and drags Angela along with them.
Once in the kitchen Jan, confronts Pam; apparently Michael told Jan that he and Pam used to date. Pam's like, "What? Noooooo." Times a million. Angela, of course, is on Jan's side again.
Out in the garage, Michael pitches Andy and Jim the idea of investing in Jan's candle company. Andy's already in, but when Jim balks, an embarrassed Michael drops the whole thing.