Roland Lasserre is a shy boy, which would be nothing if he weren't also prone to the violent tantrums that have earned him his nickname "Soupe au lait". It's when Francine announces her engagement that he decides to declare his love for her. Francine is not at all keen on the husband her parents are forcing on her - a wealthy record manufacturer - but she gives in under their pressure and asks Roland to give her up. But fate has other plans. A car accident provokes the young man's anger, and with Francine on board, he chases after the hit-and-run driver and ends up in a ditch, luckily undamaged, 50 km from Paris. Torrential rain, lack of transport, welcoming hostelry. All Roland and Francine have to do is confess their guilt, and for the sake of honor, get married... All would be well were it not for René, the neglected fiancé, who provokes "Soupe au lait" and triggers a scandal during the ceremony.