Diary of a Seducer (1996)

Student Claire lives with her mother, Anne, and Sebastien — a young man Claire brought home out of pity who is now trying to seduce them both. At school, Claire meets Gregoire, who loans her a book by philosopher Soren Kierkegaard that makes the reader attracted to whoever gave it to them. Smitten with Gregoire, Claire passes the book on to her therapist, who then falls in love with her.