In the midst of a family wedding reception Larry Kozinski (Ted Danson) meets his new cousin-in-law, Maria Hardy (Isabella Rossellini). The two soon discover that they are the unfortunate victims of an affair between their two spouses, Tish (Sean Young) and Tom (William Petersen). Deciding that the best way to get even is to get back at them in the same way the two pretend to have an affair of their own, but they can't keep up the charade when they realize they have deeper feelings for each other. When their affair begins having negative results on their families they break it off. They aren't separated for long, though, when Larry's father Vince (Lloyd Bridges) becomes enamored and they meet again at his wedding, this time under different circumstances.