Two fingers move slowly, then more firmly, faster, stretching. Aziraphale's hand moves to encourage him, and he increases his movement, timing it with the way he strokes him. He thinks, they don't have to really do it this way, do they? They are occult creatures, they could just make their bodies fit whatever way they want and then just fit, and it could be an automatic process. No stretching, no touching, no arousal. They could just put A into B and have pleasure. But there's something wonderfully sinful about doing it the human way, about having the touch and having the slowness and the movement of bodies. It's the way Crowley wants it.

All the same, the thought sparks something in Crowley, and he leans in, pressing a kiss to Aziraphale's neck that comes with more than just a kiss, but a shot of pure demonic pleasure with it. Just pleasure, something unchaste and devilish, straight from his veins to the angel's.