Bored and alone, a brother and sister turn to self-pleasure for entertainment. She fingers her wet pussy, trying to be discreet, but he walks in on her, catching her mid-act. They argue, but later, they decide to masturbate openly in front of each other. Her eyes widen as she sees his thick, straight cock. She fantasizes about it filling her tight cunt, and just as they're about to act on their mutual desire, they're interrupted.