He quickly cast a disillusionment charm on himself - he had become quite good at it from using it so often, hiding from his peers around the castle - as well as a muffliato in case anyone came too near. Reaching into his trousers he palmed his cock and sighed a bit in relief as some of the pressure dissipated with the attention. Continuing to watch Granger as she bit her lip, her hand reaching up to ghost along her neck and collar bone. All the while continuing her steady rocking.She twirled her quill in her other hand, and glanced up again. Deciding she was safe, she popped open the first few buttons on her shirt. The tips of her long feather quill danced inside of her shirt skating over what he imagined was the tops of her breasts, he couldn’t quite see from where he stood.He felt mad with the desire to see more.