The attractive Léa is around 40 and has a 20-year-old son, the result of a fleeting relationship. She lives with him in a posh studio apartment. Now Léa falls in love with David, who is supposedly an architect with a full order book and promises her marriage. In reality, however, he is a small-time employee. So that son Mathieu, who doesn't want to leave his mother alone, moves out of the apartment and goes to Canada with his girlfriend, a comedy is played for him...