As the sun creeps in, our horny brother can't resist the temptation. His cock tents the sheets, demanding attention. He slips into the bathroom, his heart pounding. The cool tile beneath his feet, the warm water cascading down, it's just him and his throbbing dick. He strokes, his grip firm, his pace quickening. The fantasy of his sister's body, her touch, drives him wild. With a grunt, he releases, his cum mixing with the water, washing down the drain.