L'ennui (1998)

L'Ennui (1998) means "boredom" in English, but this sexy flick is anything but. It opens with a divorced philosophy professor (Charles Berling) mourning the death of a colleague. Turns out there's no reason to feel sad for his dead friend, as he went out while doing the in-and-out with Sophie Guillemin, a seventeen-year-old student. Our hero takes up where his deceased pal left off. Guillemin and Berling participate in plenty of extracurricular activities, none of which involve clothing. Guillemin might get most of the naked screen time, but Berling’s no underachiever -- he even gets extra credit for bringing his ruler to class.