The thing about drinking was that Crowley and Aziraphale could do it for a lot longer than any humans. By inference, this meant they could also get a lot drunker.
They were also perfectly capable of sobering up almost instantly, but as Crowley had said more than once¹, this rather defeated the point of getting drunk in the first place. As such, they usually went for the more traditional option of passing out (albeit long after their livers, had they been doing anything other than occupying space, should have given up the ghost) in Aziraphale's back room and waking up with splitting headaches. They would then shake off their hangovers (some traditions were simply not worth it) and, depending on exactly how embarrassing or emotional or disturbingly philosophical things had gotten last night, either chat and argue and generally find excuses to remain in each other's company for a while longer or go their separate ways as quickly as possible.
On this occasion Crowley woke first, draped spinebendingly over the arm of an overstuffed chair that he was fairly certain hadn't been there before last night. He surveyed the feathery carnage around him and vaguely recalled a pillow-aided reenactment of the Last Battle, should It have been allowed to actually happen. They had called it a draw after Aziraphale's attempt to make his weapon more accurate had nearly burned the shop back down.
Crowley looked around for the angel and spotted him under the table. He had discarded his jumper² at some point and was resting his head on it, apparently having been too tired to conjure up another pillow, or else afraid that it would have become another Weapon of Angelic and/or Demonic Fury if he had.
Crowley's head was thumping. He flipped over and slid off of the chair, rubbing his temples and willing the effects of the alcohol away.
Bits of dream stabbed at his consciousness, and he paused to let the details filter into his mind. His intoxicated dreams were always either interesting or terrifying, and if they were terrifying he generally didn't remember them in the morning - he just woke up feeling very disturbed and hoping he hadn't screamed at any point while Aziraphale was still awake.³ If details were coming through, it must simply have been interesting.
Ah. Now he remembered. A party, celebrating the coming of the Apocalypse - the real deal, this time. At the Ritz. He recalled lots of confetti, punch bowls turning to blood, and Hastur chasing him across the dance floor, shouting Queen lyrics. Eric Maschwitz had headlined.
Crowley frowned, shook his head, and crawled under the table to wake Aziraphale. He was dreadfully bored, and anyway the angel hated sleeping in too late.4 Neither of them had particularly full plates today. Maybe he could convince Aziraphale to make coffee (Crowley could have done it just as easily, without even snapping his fingers5, but Aziraphale's always tasted better, somehow), and they could take it down to St. James's Park and feed the ducks.
¹Usually after Aziraphale had suggested that maybe they had had enough. At this point they were generally both too far gone to remember specific details of the conversation the next day, which was why Crowley's point bared repeating.
²Tartan. Crowley had a nagging feeling that the whole mess with the pillows had begun as an argument stemming from his honestly good-natured attempt to explain exactly why the article of clothing was not "stylish."
³He had, once or twice. Aziraphale had laid a hand on the demon's forehead and Crowley had woken up in an astoundingly good mood, immediately suspicious but preferring not to think about it for too long because he knew himself and the angel and alcohol well enough that it was easy to guess what had happened. He didn't stick around for very long on those mornings.
4Crowley had once asked him, sarcastically, if he thought it was bad for business, and Aziraphale had said that it was the principle of the matter. Crowley had muttered that it always was, and Aziraphale had pretended not to hear him because he'd really not been in the mood for an argument so early in the morning.
5He usually did anyway. He was fond of the rather theatrical cliche.