Aziraphale makes a sound of questioning surprise when Crowley bucks against him, but all is revealed to him soon enough. That request -- in that voice -- following that groan -- well, honestly, how can he possibly refuse?

One hand grips tighter in his hair, pulling experimentally, just short of actual pain. The other he places flat on the bed to give him enough leverage to push up and watch Crowley's reaction. It must be important to demand something that specific, he wants to see what effect it has on Crowley. Dimly, he's also aware of the clothes between them, as well as the fact that he hasn't bothered to shrug out of his shirt yet, but this is far more important.