In the privacy of their shared bathroom, a brother and sister, both curious and horny, find themselves alone and naked. The sister, Hetero, catches her brother's eye as he steps into the shower. She watches, intrigued, as he soaps up, his gaze flicking to her often. Mustering courage, she approaches, offering to wash his back. Their hands brush, electricity sparking. She reaches around, grabbing his cock, feeling it harden. He turns, pushing her against the cool tile, his hand sliding down to her ass, teasing her hole.