Bored and alone together, a sister and brother turn to self-pleasure to pass the time. She fingers her wet pussy, trying to be quiet, but he catches her naked in the bathroom. They argue, but later, they decide to masturbate openly in front of each other. She takes in his thick, straight cock as he jerks off lustfully, fantasizing about feeling it inside her. Just as they're about to act on their mutual desire, someone enters, forcing them to end their erotic encounter abruptly.