Breakfasts when silences are sometimes oppressive, dinners when the conversation is about every subject except sex... The daily life of a family of today is shaken when the youngest son, Romain, is caught masturbating and filming himself in the act during biology class. He risks being expelled from school. Romain explains that it is a dare that the students all challenge each other to, both girls and boys, "for fun." He just got caught.
From then on, sex, which was a taboo subject within the family, becomes a subject of interest, and we learn about everyone's private lives. We discover the sex lives of the parents, the three children aged 18 to 22, and the grandfather.