Suffering from insomnia and an acute case of hiccups, New York City socialite Jill Baker, the wife of an ambitious insurance executive, consults with the eminent psychoanalyst Dr. Vengard. Although Jill and her husband Larry are known to their Park Avenue social set as "the happy Bakers," Jill becomes distressed when Dr. Vengard questions her about her marriage, and, by the time she leaves his office, her hiccups have returned. At home, Jill faces the fact that her marriage is less than ideal when Larry, obsessed with his work, returns from the office and fails to notice that Jill has spent the entire day at the beauty salon. Jill, unable to convey her unhappiness, coolly asks Larry to stop poking her in the stomach while exclaiming "keek," a habit he thinks is endearing, but she finds annoying. On her next visit to Dr. Vengard, Jill meets a fellow patient, the cynical and brooding pianist Alexander Sebastian, who is being treated for "artistic inhibition." Sebastian, a misanthrope who habitually expresses his disdain for the world by muttering "pfui!" to himself, teases Jill after he spies a photograph of "the happy Bakers" in a society gossip magazine. Jill, fascinated by Sebastian's disregard for social conventions, accepts his invitation to a nearby art gallery. Impressed by Sebastian's worldliness, Jill invites him to a dinner party she is hosting for one of Larry's prospective clients, a Hungarian mattress manufacturer to whom Larry hopes to sell a large insurance policy. Although Sebastian insults Larry's taste in home decor and interrupts his sales pitch with his piano playing, the evening is a great success. However, after Larry goes to bed, Sebastian serenades Jill on the piano until dawn, and then kisses her. As Jill begins to immerse herself in art and music, her insomnia and hiccups disappear, but Larry grows worried that he might lose her to Sebastian. Jones, Larry's sympathetic attorney and friend, tells him to forget about insurance policies and work on selling himself to his wife before it is too late. That afternoon, Larry comes home early unexpectedly and is furious to find the obnoxious Sebastian wooing Jill under his own roof. Realizing that Jill is blindly infatuated by Sebastian's self-proclaimed artistic genius, Larry uses reverse psychology and pretends that he is willing to give her up, claiming that he too has become involved with another woman. After consulting a divorce lawyer, Larry moves into a hotel and Jill installs Sebastian in their apartment, where he spends most of his time pounding on the piano and complaining. When Sebastian leaves the apartment to pout after a petty argument, Jill, weary of his temper tantrums, visits Larry and begs for another chance, but Larry, wishing to make Jill suffer just a bit more, pretends that he has a woman in his room and is currently unavailable. As she is about to leave, Jill discovers to her delight that Larry is lying and, now certain that he still loves her, asks him for a farewell kiss, knowing that he will be unable to resist. Returning to the Baker apartment late that night, Sebastian begins loudly playing the piano in the dark and is shocked when Larry emerges from the bedroom in his pajamas to request that he play more softly. After collecting the numerous photographs of himself scattered about the Bakers' living room, Sebastian leaves in a huff, muttering one final "pfui!" on his way out. Larry locks the door securely behind him and then returns to Jill's awaiting arms.