Her brother jokes that masturbating with her nipples too much will make them hard as stone, and his naive adult sister believes every word. Desperate to stop it, she decides to absorb her brother's 'male hormones' through her pussy. Once she discovers how good raw sex feels, she loses herself in frantic pile-driver cowgirl. He warns that he is about to cum—and even tells her he already came inside—but she is too absorbed to notice. Semen spills from her pussy while she ignores every creampie and keeps accelerating her hips.