Spanking The Monkey (1994) dir. David O. Russell

Bright young student Raymond Aibelli is forced to sidetrack an important medical internship because his mother, Susan, is recovering from a broken leg. When he isnt tasked with the most mundane aspects of Susans recuperation, Raymond finds distraction in a neighborhood girl, Toni Peck. But, as Susan begins relying on her son for both physical and emotional needs, Raymond starts developing disturbing and unwanted new yearnings.