Theo couldn't have given a fuck had the curtains come down and the entirety of the Slytherin dorm were stood there staring at them, he would have stopped kissing long enough to flip them all the bird before just carrying on; nothing was going to stop him now that he had his mind set. In contrast to the strength of his will and the steel of his determination, his body was pliable and submissive to Greg's commands and he turned and lifted limbs in response to the slightest pressure of Greg's fingers.
His leg lifted up and he moaned then, light and breathy like he'd learned a long time ago to do this and not make noise. For someone who took such pleasure in physical punishment, Greg's fingers on that most delicate part of him were gentle and almost reverent.
"Yes." He answered, although it wasn't a question that needed permission, but a statement of how things were going to be. "Wait.." he reached for his wand (even now in easy reach) and cast a quick charm to silence them and ensure their privacy. He slid the wand back into a hidey place he could reach again if he needed to and then reached down to push his hands, surprisingly, under Greg's top.