The Story of Piera (movie, 1982)

Piera is a young woman who grows up under the parentage of two extremely original overseers: both her mother and father have incestuous relations with her before they are committed to insane asylums. A special connection, between a mother and her daughter, full of sensuality and complicity, has allowed to portray a family full of fears, rather unbalanced, but nevertheless searching infinite love.