Maxime is a hardened bachelor who takes advantage of his freedom and assumes to live without ties or children. Willy-nilly, he still ended up agreeing to help a couple of friends who are trying to have a child by artificial insemination, by going to donate sperm to speed up the procedure. His life changes when a rather intrusive brother arrives at his house, accompanied by a rather furry ferret, and when, in the middle of a scorching evening in gallant company, this ferret bites his private parts, rendering him definitely sterile. Realizing that he will never be able to have children, Maxime tries to recover his gift, only to learn that it has already been used for Lisa Barrot, a famous and attractive sports journalist. Aware that she will be the mother of his only child, he decides to do everything to meet and get to know her ...