Good Omens Holiday Exchange

Title: Heaven Has No Taste
Recipient: cactusrabbit
Pairing/Characters: Aziraphale/Crowley; Beelzebub, Metatron, Hastur, Ligur, & Others
Rating: Explicit [NSFW]
Word Count: 7,400
Notes: The prompt I've chosen from the set I was assigned, Crowley defects to Heaven, was evocative from the moment I set eyes on it. It's been my theory for ages that there was some kind of amnesty in the direct wake of the 1990 Armageddon Cock-Up; it makes sense to me that Heaven and Hell would arrange a meeting wherein the Metatron and Beelzebub have to act like actual diplomats and settle a truce until, well, indefinitely. As part of this, given the magnitude of what's been thwarted by each faction's agents, I'm fairly certain that individuals amongst the celestial and infernal ranks would be given a one-time chance to switch sides. Aziraphale and Crowley, of course, would be notified of this option. So it goes.
Summary: Given an unexpected choice, do you follow orders or follow your heart?