Bored and alone together, a brother and sister decide to pass the time by masturbating openly in front of each other. The sister, Michelle, starts by fingering her wet pussy and stroking her big ass, trying to be quiet. Her brother, however, catches her in the act and they argue heatedly. After making amends, they continue their erotic encounter, with Michelle fantasizing about her brother's thick, straight, huge cock plunging into her tight cunt. Just as they're about to act on their mutual yearning, someone enters, forcing them to abruptly end their taboo encounter.