In the throes of hormonal chaos, a curious sister and brother explore their desires alone in the house. She finger-fucks herself, moaning softly, while he strokes his thick cock in the shower. Caught red-handed, they argue, but lust wins out. Naked and erect, he watches her taste her own juices, and she fantasizes about his cock stretching her tight pussy. Just as they're about to cross the forbidden line, a creaking floorboard sends them scurrying for cover.