The grin is still there, still lazy - but there's a hint of something else too. Desire, at the sight of the shirt coming off; a slight tightening of the jaw when he's straddled. He doesn't pull his hands free but they certainly inch outwards a little bit, all the quicker to get them to a place where they can be used, when he's allowed. Or when the desire gets too much.

And the possession implicit in every gesture...it turns him on. He never thought it would, but it does.