Brother comes in after dance practice and sister's stomach hurts. He offers to rub it and then asks her to rub his. He gets excited and she stops. He says their stomachs probably hurts because they need to cum. She is confused and offers to show her. This leads to him helping her masturbate and her sucking his cock. Then they decide to lose their virginity to each other. She pees on him during sex and he accidently cums inside her and to get it out he sucks his cum out of her. Then Mom walks in.