Simon and Babeth are seemingly happy couple, but she is not very interested in sex, while he is the opposite. He has sex with his secretary, his older downstairs neighbor, and friend Victoria, as well as other mistresses. But Babette becomes suspicious and follows him to a hotel where he books a room to make love to one of his mistresses. She books the adjoining room and manages to spy on them. This turns her on and Simon persuades her to get involved in the swinging scene with the help of his friend Victoria, but first he takes her to watch the goings on in the Bois de Boulogne and persuades her to give him a public blow job. They attend a club échangiste run by France Lomay, and several orgies, finally holding one themselves.