L’enfer (1994) by Claude Chabrol
aka: Hell, Jealousy

Suddenly everything starts to make sense. The puzzle is completed, the truth is clear as crystall and awkwardly visible for everybody. His lovely wife has been (is) cheating him. Right in front of him. He saw it with his very own eyes. First with Martineaux (Marc Lavoine), one of the waiters, and then she seduced frivolously one hotel guest after the other, sneaking out during the night, while he was asleep, and off she run, into their beds. And she (Emanuelle Béart) really thought he (Francois Cluzet) would be too stupid to detect her lies? Oh no! No, no.

seen at: pickledfeet private videothek