L'Ennui (1999)

The title means discontented boredom in French, and it is the peculiar ailment of Martin, a very unhappy philosophy professor. When he picks up the tab at a bar for a poor artist and receives a painting for his troubles, it leads to a relationship with one of the artist's models -- a 17 year old beauty named Cecilia. Soon, the two are engaging in daily rendezvous that quickly become an obsession for Martin, who has realized that Cecilia is something of a blank slate -- she shows no emotion during their wryly explicit lovemaking and Martin begins to think her soulless. However, when Cecilia begins to skip some of their appointments, Martin grows obsessed with possessing all he can of this voluptuous nymphette, sending him into a downward spiral of misery and existential crises.