Luciene, convinced by her friend Mariana, joins the "Club of the Unfaithful", to make her husband Alberto jealous. The condition to enter the club is to have a lover, and Luciene suggests an affair with the club director's husband. The betrayal annoys the director and causes misunderstandings between the members during her reception party. Husbands flirt with the new associate and the "infidels" lose their composure, triggering embarrassing and even tragic events.