The siblings' secret late-night encounter begins with a soft knock on the bedroom door. The brother, already aroused, quickly hides under the covers as his sister enters, locking the door behind her. She climbs onto the bed, straddling him, and whispers, "I've been watching you. I know what you like." She reaches under the covers, wrapping her small hand around his hard cock, and leans down to take him into her mouth. Her inexperienced tongue flicks against his sensitive skin, sending shivers down his spine as she tries her best to pleasure him.