After having gone to the theater by himself, Ralph arrives at his Paris suite one night to find Undine with Peter Van Degen. Undine is sitting at a coffee table with Peter on the other side. Peter is stretched out a little too casually in his chair, Ralph notes, as if the man were in his own home. The scene looks very intimate to Ralph, and he is immediately on guard. When Ralph enters the room, Peter does not move to greet Ralph but merely says hello. When Ralph looks to Undine for a reaction to the laxness in Peter’s manner, he finds none. But Ralph sees that his wife’s face appears illuminated, which look Ralph finds disagreeable because the source of her excitement is Peter Van Degen, a man Ralph finds a bore and a nuisance.

As Ralph stands there, his wife and Peter mock him for the type of theater he prefers. Ralph goes to watch intellectual dramas, whereas Peter and Undine prefer the more entertaining Folies Bergere, a dance revue. Peter suggests that Ralph should take Peter’s wife to the theater because she likes the intellectual. Meanwhile, Peter will entertain Undine. Peter emphasizes his suggested marital switch by stating that the trick is for a man to marry a woman who does not like to do what he finds enjoyable, so then he will be free to go out and find a woman who loves everything he likes and then he can make love to her.

After Peter leaves, Undine tells Ralph that she has come up with a scheme so that it will not cost them any money to travel home: she has talked Peter into sailing them home for free on his yacht. Ralph is so much against this idea he finally stands up to Undine and all her demands and insists that she write a note to decline Peter’s offer. Later, when Ralph goes out to visit with his cousin Clare, who is married to Peter, Clare warns Ralph not to allow Peter to “make a goose” of Undine. Ralph claims that Undine is well equipped to defend herself. Clare insists that her husband is out to capture Undine in some way; she senses that Undine loves to be amused, and Peter is a master of fascinating entertainment.

As the time for their departure from Paris nears, Ralph is amazed at how many purchases arrive at the suite, delivered in boxes by porters. The packages take up most of the room in the apartment. One day when he returns, Ralph finds Undine lying on the couch, completely exhausted. When he asks if the packing of all her dresses has worn her out, Undine begins to cry. She tells him that it has just been confirmed that she is pregnant. The news has come as a shock to her. This means that she will have to spend almost a whole year outside of the activities of society upon returning home. There is no sense of jubilation over the news of her pregnancy from either prospective parent.