Tinto Brass Presents Erotic Short Stories: Part 4 - Improper Liaisons (1999)

Following the death of her mother, Silvia leaves boarding school to stay with her recently remarried uncle in Rome. Everyone welcomes Silvia into the household, except her cousin Elena - who knows her flirtatious cousin better than the other family members. In no time at all, she updates her younger cousin, Marco, on the game of "doctor" they played in their youth. Then, sensing her aunt's maternal disposition, she allows herself to be babied in a mutually enjoyable way. When Elena confronts her uninhibited cousin, demanding she leave their home, Silvia suggests it will be Elena and not she who will make an exit. Soon thereafter, she seduces Elena's boyfriend, bestowing the oral gratification that Elena had thus far refused him. And lastly, Silvia ascertains her uncle's passion for photography masks a deeper passion for voyeurism, and invites him to watch as she has sex with his son Marco - after which she charitably relieves his arousal with a hand job. Elena witnesses her father's seduction, and things unfold as Silvia had predicted.