La Chiave (1983)

Director: Tinto Brass
Cast: Armando Marra, Barbara Cupisti, Franco Branciaroli, Frank Finlay, Gino Cavalieri, Maria Grazia Bon, Piero Bortoluzzi, Stefania Sandrelli

Synopsis:

Art professor Nino Rolfe attempts to break down his wife Teresa’s conventional modesty. Noticing her affection for their daughter’s fiancé, Nino instigates her sexual interest in him – setting off a chain of unexpected events and emotional complications…