A brother, hidden behind the bathroom door, watches his sister's lewd display, his cock hardening at the sight of her bare flesh and the sound of her relief. He can't help but stroke himself, his breath hitching as she continues to mark the hotel floor with her piss. He imagines her tight cunt, wonders how it would feel to fuck her right there on the cold, wet marble. But his fantasy is interrupted as their mother's voice echoes through the room, forcing him to rush back to his own room, his cock still hard and aching for release.