More Aziraphale & Crowley wing thoughts - 

Yes, they have wings. Of course they do. Fallen angel or standard issue, it goes with the package.

And the wings are always there, except they aren’t quite there.

Angels and demons can see each others’ wings - well, not quite see. Perceive. And they can gesture with them, and stretch them widely to get the kinks out, and shed feathers on everything; they’re always there.

But celestial wings don’t quite fit into the human realm, so if one is in a human form, one’s wings aren’t noticeable or even perceptible by any human sense unless the celestial being in question wants them to be.

So there is the occasional awkward situation when, for example, Aziraphale, making a point to a friend as he strolls through the park, gestures emphatically with a wing and accidentally sticks it right through a typical human passerby. No harm done, of course, aside from it feeling quite weird.[1] Not bad weird, necessarily. But being imperceptibly impaled with an angelic appendage does leave a psychic imprint, a bit like having forgotten something rather nice.[2]

1. Not weird to Aziraphale, of course; he probably doesn’t even notice unless Crowley sort of points and goes… “um… you’ve… got a thing…” ↩
2. When Crowley does it, it’s definitely bad weird. And whatever it is it feels like you’ve forgotten, you really hope you don’t remember. ↩