Under the same roof, a brother and sister find themselves alone and horny. The brother, hard and aching, can't help but stroke his thick cock, his eyes wandering to his sister's closed bedroom door. She, too, is playing with herself, her fingers buried deep in her wet pussy, imagining her brother's cock filling her. Their mutual masturbation escalates to a fever pitch, their moans echoing through the house, until they climax together, their bodies shaking with the intensity of their forbidden pleasure.