In a steamy, cramped shower, a brother and sister, both horny and frustrated, find themselves alone together. The sister, her body glistening with water, tentatively reaches for her brother's growing erection. He's thick and hard, and she can't help but stroke him, her own pussy throbbing with need. They're both scared, but the excitement of the forbidden is too much to resist. She lowers herself onto him, gasping as he fills her. They fuck frantically, water pounding down on them, until they both climax, their cries echoing in the small space.