Based on the play Fleur de cactus by Pierre Barillet and Jean-Pierre Gredy, the comedy focuses on the relationship between young, wild Toni and her older, married lover Julian, a dentist. Convinced the two have no future together, Toni attempts suicide, and a guilt-ridden Julian rashly proposes he leave his wife so the couple can be together. However, Julian has never revealed to Toni that his "marriage" is actually an elaborate lie concocted to keep Toni at arm's length. Toni refuses to break up his household without first meeting and talking with Julian's soon-to-be-ex, so Julian enlists the aid of his shy spinster assistant Stephanie to pose as his non-existent wife. Complications arise when Toni decides the two must find her a new beau so everyone concerned can live happily ever after.