The moaning and internal stuggle only encourages him further and he does it again and again and again because anything that gets that sort of reaction from the man is a good thing. Then he raises himself on his hands and knees so he can get deep and starts working properly - still with care, still measured...but intense, taking him deep and swallowing round him, using his tongue artfully, moaning at the taste of him already and flicking over the tip when he comes back up.