Plot
In an unnamed American city, two middle-class couples deal with their unhappy relationships by experimenting with adultery. Jerry is a neurotic, self-obsessed college drama professor whose live-in girlfriend Terri, a copywriter for tampon boxes, is unsatisfied by their relationship due to his penchant for talking during sex. Mary, a freelance writer friend of Terri's, is married to Jerry's best friend Barry, a business executive who feels that no one can satisfy him sexually more than himself and is oblivious to Mary's sexual frustration.
When Jerry and Terri have dinner with Barry and Mary, Jerry secretly propositions Mary, confessing that he cannot stop thinking about her since they last saw each other. Mary admits that she has thought about him as well and accepts his offer. The next day, Terri meets and begins a secret romance with Cheri, a lesbian assistant at a local art gallery. Terri feels sexually satisfied with Cheri and enjoys their quiet moments, as opposed to Jerry's talkativeness.
Meanwhile, Cary, a doctor friend of Barry's, is a callous, manipulative womanizer who preys on naïve and emotionally vulnerable young women, using them for sex before remorselessly discarding them.
During Jerry and Mary's rendezvous at a local hotel, he is unable to perform sexually, prompting Mary to abruptly end their brief affair. A few days later, her frustration grows when Barry unwittingly takes her to the same hotel room to rekindle their romance.
In a sauna, Barry asks Jerry and Cary to reveal their best sexual experiences. In response, Cary recounts an incident in high school when he and three of his friends gang-raped a male classmate. Barry and Jerry are stunned yet intrigued by Cary's story. When Barry tries to persuade Jerry to reveal his best sexual experience, Jerry refuses. After being goaded in the locker room, Jerry angrily responds that his best sexual experience was with Barry's wife and leaves. Barry is speechless, while Cary, also caught off-guard, says, "That beats my story."
Terri is heartbroken after finding Mary's phone number in one of Jerry's playbooks. At a bookstore, Cary recognizes Terri and asks her out on a date, but after she rejects him, he verbally abuses her and accuses her of mistreating Jerry. During a chance encounter with Mary, Jerry seeks closure and proposes that they talk, but she berates him for suggesting the same hotel room to Barry and leaves him. That night, Barry confronts Mary about her affair with Jerry. The next day, Barry visits Jerry during a dress rehearsal, and Jerry apologizes for his indiscretion.
Jerry confronts Cheri at the art gallery over her affair with Terri, trying to understand why Terri would be interested in Cheri, but Cheri dismisses him for saying "stupid fucking things" to people. Over lunch, Jerry attempts to reconcile with Terri, acknowledging that they both made mistakes, but she nonchalantly breaks up with him.
Jerry continues his philandering lifestyle with his female drama students, though is still dissatisfied. Terri moves in with Cheri, although she quickly finds her emotional neediness irritating. After divorcing Mary, Barry can no longer achieve an erection even while masturbating. Mary moves in with Cary, who pressures her into sex and treats her coldly while she is pregnant with his child.
