The Girl and Horse(1983)

Marcia, a nymphomaniac girl postpones the marriage with her fiance, Beto, because they have some problems and goes to the family farm with him to have a rest. There, her young and sexy stepmother is attracted to the boy, seduces and sex with him. Meanwhile she reunites with the stable boy, Juka her childhood friend and Ariscu, the horse from her childhood and begins to live sensual moments with the animal with which she had a relationship once.