Teorema (1968)

aka: Theorem

A stranger (Terence Stamp) visits a wealthy family. He seduces the maid (Laura Betti), the son (Andrés José Cruz Soublette), the mother (Silvana Mangano), the daughter (Anne Wiazemsky) and finally the father (Massimo Girotti) before leaving a few days after. After he’s gone, none of them can continue living as they did. (In Italian language, with English subtitles).