In the dim light of their shared room, siblings indulge in a secret ritual, the religious texts they're supposed to be studying forgotten. She guides his hand between her legs, showing him how to touch her, her breath hitching as his fingers find her clit. He's inexperienced, but eager, his cock hardening as she teaches him what she likes. Their bodies press together, their breaths mingling, as they cross the line from innocent to taboo, their moans masked only by the rustling of pages.