Salut, j'arrive (1982)

Gérard Travers has known Minou since childhood. After completing his military service, he moved in with her, in all honor, until he could find something better. Together, they establish a protocol for living harmoniously as roommates without stepping on each other's toes, but little by little, Gérard becomes irresistibly attracted to Minou and vice versa. They realize that they've always been made for each other.