Love Me If You Dare (2003)

Julien Janvier lost his mother young, drifted apart from his working class father and ever closer to confident Sophie Kowalsky, the Polish class outsider. Their dares game, symbolized by an interchanged music-box, grows ever bolder, regardless of harm to others and each-other.

In his college years, it even suspends their relationship and toys with their marriages, but they are drawn back to each-other irresistibly.