Lionel is a seducer. His success with women provokes his friends jealousy. One of them, Alain, challenges him to seduce a beautiful woman chosen at random, to fall in love with her and spend a night with her without making love. Claire is the chosen victim. Behind Claires prim and proper facade there lurks a lusty, full-blown and demanding sexuality. The self-control that Lionel imposes on himself (with difficulty) to win his bet begins to intrigue Claire. She decides to take the offensive. As Alain tells the story to young Sophie on a café terrace three years later, Lionels misadventures comically upset several popular prejudices concerning virility and male sexuality.