Confessions (1977)

Beth, a bored housewife who can't get sex from her moron husband Gary, and goes out looking for it. First she picks up a biker, then seduces her husband's boss Tom. She answers an ad in the paper and humiliates Howard, much to his wife's amusement, before letting herself be with the wife as well. Eventually, she turns to prostitution, but unfortunately quickly learns the reality of such a lifestyle.