I kind of headcanon that both Aziraphale and Crowley have a sort of ‘vital signal’ displayed on some monitor in each Head Office somewhere. Some kind of ethereal chord humming for Aziraphale, some kind of hissing whine for Crowley, and it comes through strong to let whoever’s supposed to be monitoring the field agents know that everyone’s doing well. For the Heavenly field agents, it’s an enormous glorious building symphony; for the Hellish variety, a perfect layering of thousands of nails on a world-sized chalkboard.

But when Aziraphale and Crowley are together… like, easily as air with air kind of together… things get a bit… distorted.

“Oh, ouch,” said the angel with irritation, yanking off their headphones and staring at them.

“What’s wrong?” asked their shift partner.

“It’s gone all funny again,” said the angel, knocking the headphones against the counter a few times. “I can’t fathom it. Just lately, there’s this terribly irritating buzz in the feed.”

“Well, who is it?”

“It’s… mnnn…” They look up at the monitors, and it’s not hard to pinpoint: one vital line is fuzzing out like an oscilloscope picking up a hard rock concert. “Oh, it’s them again.”

“Aziraphale,” sighs the other angel, like a curse. “What is that angel doing?”

“I don’t know. It always goes away. There’s quite a lot of interference on some of these older signals, you know.”

“We should really have them back up for a good retuning. They could use it.”

“We’ve sent notifications; they never come. Really, one wonders what good typing up the notification is if they aren’t even going to answer.”

“Part of the job, one must be responsible…”, and they both stare up at the monitors, waiting for the signal to clear itself out again.

Meanwhile, somewhere else, a demon has turned its third pair of headphones into a steaming pool. It’s never going to get that celestial song out of its head.