Pierre has been happily married for fifteen years and a good father. Still in love with his wife, he enjoys his wife and family and is content. One evening, he meets Elsa at a party and are immediately attracted to each other. Fifteen days later, they happen to meet again and the mutual attraction turns into infatuation. But his love for his wife and Elsa's rule about not dating married men prevents them from taking the next step. Instead, they fantasize about each other, and soon the fantasies mingle with the reality.

In this very light romantic comedy, two young men who are in search of the hypothetical perfect woman believe they have found her at a wedding reception. There, they see Lisa. Alexandre is the shy one, but he is also the one with the greatest yen to meet such a woman. He and Romain track Lisa down the next day and, though she is already dating someone, when Romain approaches her, she agrees to meet the two of them at a restaurant. They are dismayed when the part-Italian girl brings her mother with her as a chaperone. Other difficulties arise as well, and they resolve that this quest is less important than their friendship. Besides, Alexandre has by now discovered the charms of Romain's younger sister.