In the dim light of the bathroom, a brother and sister, bored and curious, find themselves alone. Their eyes meet as they masturbate, the air thick with tension. She strokes her pussy, her moans matching his grunts as he jerks off. Their eyes lock, and in a flash, they're entwined, her wet cunt enveloping his throbbing cock. They fuck hard, their bodies slapping together, until they're both gasping, their cum mixing as they collapse, panting and sated.