Delphine and Yvan divorce. While his financial situation does not allow him to find a home, Yvan remembers that he owns 20% of his ex-wife’s house. He then returned to live with Delphine, in his 20%. The two ex will discover the joys of forced housemates.

Éric and Patrice have been friends since high school. Over the years, they have both taken very different paths: Éric has become a hedonist, has a string of girlfriends and is always on the look out for a new one; Patrice has become a monogamous father with a very ordered life. After a drunken evening, the two childhood friends find themselves cast back into 1986, when they were 17 years old. This return to the past is a dream opportunity to try to change the path their lives will take. What will they do with this second chance?