Frustrated siblings, left alone together, can't resist the temptation. She strokes her clit, moaning softly, while he jerks off to her naked form. Caught in the act, they argue, but desire overpowers anger. Naked and horny, they masturbate openly, fantasizing about each other. Just as they're about to cross the final boundary, a sudden noise forces them to pause, leaving them breathless and aching for more. -