This is a very new reaction to killing someone and he has to admit that he prefers this, at least with the relationship they got going. Maybe it wouldn't be so terrible to give Jack a love bite when they're awake either... a thought he'll be quick to kill once he's come to. No biting. No real biting - well, no digital real biting. Fuck.
He gives Jack a look, wiping at the cooling blood on his chin and licking his fingers clean. Wouldn't mind putting that mouth to work but on the other hand...