The Seduction of Mimi (1972)

Mimi is a Sicilian dockworker who loses his job when he votes against the Mafia candidate in what he thinks is a secret ballot. He leaves his wife behind and goes to Turin, where he meets and moves in with Fiore, a street vendor and Communist organizer. They have a child, he works non-union jobs, and again he comes to the Mafia's attention. This time they're impressed, promoting him to a supervisor's job back in Sicily. He must keep Fiore and the child a secret, which is fine with Fiore, as long as he never makes love to his wife. He doesn't, and when she becomes pregnant, he knows he's a cuckold. His personal revenge and the Mafia's tentacles then intertwine in tragicomic ways. IMDB