The Fallen Guardian

All Crowley wanted, was to spend time with his Angel. Instead his is sent off to the states by Hell, who haven't contacted him in YEARS. So he hopped across the pond, with a little bit of guidance, and soon to be therapy, from Aziraphale on the phone. Crowley did a little snooping.
He wasn't fond of what he found.

"Another Bloody Apocalypse! We just stopped the last one!!"

The Winchesters aren't the only ones that deal with Demon and Angel crap. What would happen if they were to meet Crowley? What if they met him before long ago in their childhood? What happens if Crowley were to join Team Free Will with assistance of his ineffable husband?

(This isn't my best summary but please read before you decide whether or not your interested. Updates will be slow and/or infrequent.)