The Heartbreak Kid synopsis
Soon after Lenny (Charles Grodin) marries Lila (Jeannie Berlin), the needy and unrefined side of her personality begins to emerge, and he becomes increasingly uncertain about his decision to marry her. During their honeymoon in Miami, Lenny meets beautiful and sophisticated Kelly (Cybill Shepherd). Every chance he gets, Lenny sneaks away from Lila to be with Kelly, and the more he gets to know her, the more he falls in love. Problems arise when the two women learn about each another.