In the confines of their room, a brother and sister act on their secret desires. She climbs onto his lap, feeling his hard cock straining against his jeans. He kisses her neck, hands roaming her body, cupping her breasts. She grinds against him, whimpering as he slides a finger inside her. They're lost in each other, bodies moving in sync, until a creaking floorboard snaps them back to reality. They freeze, hearts pounding, as their mother's footsteps echo down the hall.