The steam from the shower billows around them, blocking the world outside. A sister and brother, bound by blood and desire, find themselves in a dance of restraint and release. She steps closer, her eyes locked onto his, as he reaches for the soap, his hands trembling slightly. He lathers up, his touch turning from innocent to intentionally sensual as he runs his hands over his body, his cock throbbing with each pass. She can't help but watch, her own body responding, her breath hitching as he turns to face her, his eyes filled with a hunger that mirrors her own. They stand there, on the precipice, before she takes a step forward, her body brushing against his, their lips inches apart, ready to plunge into the forbidden.