He could almost have sobbed when she rubbed into his hand.  What people didn't understand about demons is that they lived in a world of intense extremes.  Everything they felt, they felt to excess.  So that gentle rub into his hand was as profound to him as a passionate embrace would have been to most humans.  He could feel her continue to drink, and each pull now elicited from him a moan, and a rumbling purr deep in his chest, like a great panther.