The Dambreuses invite a few "intimate friends" to their home, including Frederick, the Arnouxes, Cisy, Martinon, Monsieur Roque, and Louise.
When Frederick arrives, Monsieur Roque asks him where he has been. He claims he's been spending time with a wounded friend.
Martinon asks Monsieur Dambreuse if he can marry his niece, Cécile. (He actually suspects Cécile is really Monsieur Dambreuse's daughter, which would mean a better dowry for him). Madame Dambreuse isn't happy about the whole sitch; she wanted her niece to marry Cisy because Martinon is her lover.
So. Many. Love. Triangles.
More talk gets going about insurgents: wealthy citizens are worried they'll lose everything with the fall of the monarchy.
Mr. and Mrs. Arnoux waltz on in, and Frederick ends up seated next to Madame Arnoux. How convenient.
The two almost-lovers have a whispered argument.
Cisy and Martinon begin to battle for Cécile's attentions. Martinon embarrasses "the Vicomte" (Cisy) by bringing up the duel with Frederick, and Cisy's lack of courage sends a buzz around the table.
Then Frederick becomes embarrassed when Roque begins asking questions about "a very notable picture" of Rosanette, which he and Louise had seen at Frederick's house when they tried to visit him. Madame Arnoux puts two and two together is majorly ticked. It's clear to everyone that he and Rosanette are lovers.
A guest named Fumichon goes on a tirade about the natural law of owning things; to him, it's an animal instinct.
They also discuss the on-going tension between the workers and the bourgeoisie.
Madame Arnoux and Louise have a chat in the garden about Frederick. The lady tries to tell the young girl not to believe everything that a man says. Louise doesn't buy it, and in fact, they're each suspicious of the other.
Madame Dambreuse teases Frederick about Louise's obvious crush on him, and says she thinks Louise is ugly. Good comeback?
As they're all leaving, Louise tells Frederick that all of the women at the party are nasty gossips. She's also upset that he has ignored her for so long. She pressures him to marry her, but he couldn't be less interested. He puts her off by saying he has business to attend to—not to mention that pesky political uprising.
Then he promptly hightails it to Rosanette's.
That night, Louise and her maid sneak over to Frederick's house for a late-night rendezvous, but he's not there—and the concierge tells her that he hasn't slept at home for three months.