Having fortuitously discovered a photograph in which Marthe embraces someone unknown, Étienne Dorsay becomes jealous and imagines various stratagems to identify the lover. In the meantime, he and his friends acquire a weekend house for a very low price.
Jean Rochefort
as Etienne Dorsay
Claude Brasseur
as Daniel
Guy Bedos
as Simon Messina, doctor
Victor Lanoux
as Boulifet, aka 'Bouly'
Danièle Delorme
as Marthe Dorsay, Étienne's wife
Marthe Villalonga
as Mouchy Messina, Simon's possessive mother
Jenny Arasse
as Bernadette, designer collaborating with Étienne
Josiane Balasko
as Josy, Lucien's girlfriend
Anne-Marie Blot
as Marie-Ange, Bouly's ex-wife
Elisabeth Margoni
as Daisy, Bouly's fiancée
Pascale Reynaud
as Delphine, Étienne's younger daughter
Maïa Simon
as Madame Chalamand, Simon's lover
