Original title (FR): Le Syndrome des amours passées (Past Love Syndrome)

Remy (Lazare Gousseau) and Sandra (Lucie Debay) can’t have children because they suffer from the “Past Loves Syndrome”. To heal, there is only one solution, they must sleep with all their exes once.

https://www.themoviedb.org/movie/989232-le-syndrome-des-amours-passees