Oh, he's not about to stop. Not about to stop, but instead to speed up the pace, moving ever quicker, just enough to bring Aziraphale as much pleasure as he can, and then slow down again, keeping him from going too far over the edge.

After all, they do have all night. And while Crowley doesn't have the ability to stop time for more than a few minutes, he can make this last as long as they want it for.