The Bishop's Bedroom (La stanza del vescovo) (1977)

In this drama, Temistocle Orimbelli (Ugo Tognazzi) is a middle-aged man with a profound appreciation for womankind -- an appreciation that does not extend to Cleofe (Garbiella Giacobbe) his dried up old shrew of a wife. He is much taken with the charms of his sister-in-law Matilde (Ornella Muti), who is a widow. The attraction appears mutual, but he has first to overcome the obstacle of wifely suspicion in order to consummate the union. Eventually, he is able to appear at his boat at the same time as the lovely Matilde, and what had begun as a simple assignation turns into a complex tragedy. ~ Clarke Fountain, Rovi