Aziraphale wraps his arms around him, and Crowley can't really do much more than return the gesture. To hold the angel close, to keep him right there, near him.

And now, somehow, he's supposed to walk Aziraphale right into danger. Right into Heaven and Hell's arms, and demand things on behalf of the human race. Well, the human race can stuff it, too, for all Crowley cares. All he wants to do is protect the angel.

Of course, that also means doing the right thing. Aziraphale would want to do the right thing and he won't be happy if they don't. And what Crowley wants is to make the angel happy.