If he weren't in such a state, he'd give an amused smile at the break in Crowley's nonchalance. A wily serpent, but one who loves him. One the angel trusts completely. He kisses back, eyes shutting, giving himself over to the demon's ministrations.

Fortunately for Crowley, Aziraphale is even more vocal about how he likes his cock to be touched than he is about the food he likes to eat. Not so much in words, although there is a "yes, there" and "more, please" thrown in among the gasps and whines of pleasure. It's all nearly indistinguishable at first, every touch new and sensitive, but as Crowley strokes and twists and swipes just right, it becomes clear what keeps him hard but steady, and what jolts him to a new level of passion.

It's not long before that sensation builds, coils like a spring deep within him, like the tensing of his wings before he's about to fly. It's otherwise unfamiliar, but he's read enough of metaphorical trains through tunnels and falling off of cliffs to know what's coming.

(...oh. Is that why humans call it that?)

One hand continues to grasp at the sheets, the other finds its way back into Crowley's hair, tugging a little as if in warning. "Crowley -- oh, oh, Crowley, darling, I -- I think I might be close --"