As Aventuras Amorosas de Um Padeiro (1975)

In the suburb of Rio de Janeiro, the virgin student Ritinha marries the morally conservative low middle class tacky car dealer Mário, but a couple of months later she becomes very disappointed and bored with their sexual life. She has one night stand with the stupid Portuguese baker Marques, who has a crush on her, and a friend of Marques takes pictures of them having sex in his cottage. When Rita meets the black artist Saul in Pedra de Guaratiba, they become lovers, and Marques completely jealous with the situation discloses the pictures to Mário, tearing his predictable world down.