Moment by Moment (1978)

Synopsis
John Travolta played his first romantic lead in this drama about an ill-fated May-September romance. Trisha (Lily Tomlin) is a wealthy middle-aged housewife living in Southern California. Trisha's life has become dull and uneventful, and her long-term marriage to Stu (Bert Kramer) has gone stale. One day, a handsome young drifter named Strip (Travolta), nearly 20 years her junior, happens along the beach near Trisha's house. He finds Trisha attractive, and he approaches her. Soon the two have fallen into an affair, but while Trisha enjoys Strip's company and thinks that he's handsome, it's obvious that he's more interested in her than she is in him. Moment by Moment was written and directed by Jane Wagner, Lily Tomlin's longtime companion and frequent writing partner. ~ Mark Deming, All Movie Guide