Remember: everything Crowley says is made up.

Crowley would poke his head out from behind some bookshelves at the sound of the bookshop bell, lingering on you a second too long before seemingly coming to a decision. In one swift movement he makes his way over to you, expression unreadable behind his sunglasses. He stops a few steps ahead of them, hands in his pockets and seemingly annoyed. "Aziraphale isn't here right now- sorry to be the bearer of bad news. If you want a book were not selling it." He would lean his weight on a nearby bookshelf, not once taking his gaze off of you. Sure enough, you didn't see the infamous Mr.Fell who owned this bookshop. Or any other customers for that matter.