Lucile, 25, is the beautiful mistress of Charles, a rich, good-hearted businessman. Being a kept woman suits her as she refuses to work. She is grateful to Charles for that but she does not feel true love for him. When she meets Antoine, a charming young man of her age, it is love at first sight. But living with Antoine is not as easy as it was with Charles: Lucile is forced to find a job, which she hates. Moreover, she gets pregnant and has to ask Charles for help. After having an abortion, her love for Antoine gradually fades. That is the reason why she comes back to Charles who, full of indulgence, has patiently waited for her.