Threesome Wild (1990)

Following a love disappointment with Carmen, Perry moves to Miami to study in medical school, where his uncle Wilfred is a teacher. He rents a room from middle-aged Laurie, a friend of his mother's. She lives with her stepdaughter Sheila. He is attracted both women. He begins to dream about a beautiful Sheila. They soon become very good friends, but Perry did not know that she, unbeknownst to her stepmother, secretly serves as a nude model in adult magazines.