A brother and sister, left alone, can't resist the temptation to masturbate. The brother, hard and throbbing, finds his sister in the throes of passion, her fingers deep inside her wet pussy. They argue, but the sight of each other's naked bodies is too much. She takes his huge cock in her hand, feeling it pulse with need. They fuck hard and raw, caught in the act but unable to stop, their taboo lust consuming them.