Le cri du coeur (1974)

Alexandre, the neglected teenager son of a a wealthy couple, Claire and Mathieu, finally gets some attention when he has a very serious accident while climbing a tree: it leads to the amputation of one of his legs. As a result he becomes hysterical and troubled by sex. Obsessed with sex, he cannot have an affair with a girl and this turns him into a perverted, manipulating little jerk. He blackmails his mother when he discovers she has a lover. His growing problems become more complex when he falls in love with Bunkermann, the wife of his father's boss.