George, in low spirits, confesses to Jerry, Elaine, and Kramer that his mother found him masturbating to her issue of Glamour. With his mother hospitalized after throwing out her back in horror, George swears off masturbation "altogether", to everyone's incredulity. George challenges Jerry to a wager to hold out the longest; the others ante up as well, but, giving women "two to one" odds over men, they make Elaine put up extra.
Through Jerry's window, a naked woman can be seen in an apartment across the street. As George and Jerry peep transfixed, Kramer discreetly exits, then returns, declaring "I'm out!" and pays up. George's mother, in traction at the hospital, harangues him and demands that he see a psychiatrist for what he did. When George's cousin Shelly starts asking him about his writing job for NBC, he becomes titillated by the silhouette of a female patient receiving a sponge bath by a nurse behind the divider curtain.
Elaine starts an aerobics class, where, as an unexpected bonus, John F. Kennedy Jr. is also working out. Starstruck, Elaine pretends to live at Jerry's building just to share a taxi with Kennedy. Jerry is sexually frustrated by Marla's hesitancy to lose her virginity to him. That night, Kramer sleeps soundly while the others sleeplessly hold out.
Jerry is desperate to shut out the naked woman, but Kramer is equally desperate to continue peeping, and Jerry resorts to distracting himself with cartoons on TV. George feigns filial devotion to visit his mother again during sponge bath hours, but plays for time as she begs him to get her a sandwich. Kennedy has asked to meet Elaine again at Jerry's building, enrapturing her. That night, she gives in to her fantasies.
Elaine pays up while Jerry and George, after two restless nights, snap at each other over a pair of socks. Later, Marla is finally ready for sex, and Jerry relievedly comes clean about the contest. Marla denounces the entire group and leaves in horror. Elaine misses Kennedy's arrival, and he finds the distraught Marla instead, consoling and leaving with her.
Despite dropping out first, Kramer has come out on top by hooking up with the naked woman, as the others look on enviously. That night, everyone sleeps soundly, the contest now moot. Meanwhile, Marla has blissfully lost her virginity to Kennedy.