Paris and its suburbs. Two stories, four girls, four boys, on one summer day that will change their lives forever.

One evening, in his apartment in Paris, Lorenzo is getting ready to receive Marvin for the first time, a boy he really likes. Marvin shows up at the door with Thomas, a homeless man he met on the street in need of a shower. Lorenzo doesn’t dare say no.

Remy and Sandra 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.