It isn't a matter of not wanting to. [Or of wanting to leave, which he finds on a moment of consideration that he really doesn't want to do just yet. He brushes his fingers against Luke's hair, tucking a little of it behind his ear.]

I just don't want to injure you, that's all.

[Even things that felt good could be dangerous. Still, he leans slightly and brushes a soft and gentle kiss to the young man's lips.]

We can keep going. You just need to tell me if something feels wrong.