Watch That Splendid November

"That Splendid November" (1969) is an Italian movie about a Sicilian youth born to a very liberated family. His mother has lovers on the side and his father seems to accept this arrangement. The youth himself falls in love with a very attractive aunt -- who also has affairs with other men. He's infuriated by her faithlessness. His family then pressures him into marrying a girl his own age. He does so, but he never stops loving his aunt.

The film is based on a novel.