In the quiet of their home, a brother and sister find themselves alone and horny. She starts masturbating, her fingers dancing over her clit, while he watches, stroking his hard cock. Caught in the act, they argue, but lust wins out. Naked and vulnerable, they masturbate openly, her eyes locked on his massive cock. Just as they're about to cross the final line, a sudden noise forces them apart, leaving them breathless and yearning.