Warnings: Demon sex ;)

A/N: Just a silly little demon AU, thanks for reading!

Merlin's first day in hell gets off to a bad start. He blames residual sea sickness from Charon's little boat ride, but he's barely gone ten paces before he's walked bang into someone.

"Sorry, mate," he says easily but the blond man in front of him looks weirdly outraged.

"Do I know you?"

"I'm Merlin," he says, sticking his hand out politely. Just because this was hell, there was no need to forget his manners.

"So I don't know you?"

"Nope."

"And yet you called me mate?"

Merlin narrows his eyes.

"That was my mistake."

"Yes I think so," the blond says smugly.

"I'd never have a friend who'd be such an arse."

There's a few whoops from some of the onlookers, and Merlin turns to leave, satisfied he'd put the man in his place.

He's barely taken three steps when the ground cracks open in front of him, fire and lava bubbling up until he's forced to retreat back the way he came.

He turns around and the blond's still standing there. Only he's undergone a slight transformation in the last five seconds. His eyes are burning red, there's a pair of black horns protruding from his forehead, and good God, is that a forked tail?

"Tell me, Merlin, do you know how to walk on your knees?" the man hisses, his tail cracking through the air like a whip.

"No," Merlin says, gulping as the flames lick a little closer to him.

"Would you like me to help you?"

There's a sizzling sound and Merlin finds himself suddenly forced to his knees, like an invisible hand's pushing him down.

"This totally doesn't count!" he says indignantly.

"Oh I'm going to have fun tormenting you," the blond smirks, baring his perfectly pointed teeth.

"Who do you think you are?" Merlin grits out. "Satan?"

"No. I'm his son. Arthur"

Oh, bollocks.

First day here and he pisses off the Prince of Hell. That's just great.

Still Merlin's never been one to roll over and admit defeat when he should, so he says:

"Look, I've told you you were an arse. I just didn't realise you were a demonic one."

Seemingly against his better judgment, Arthur barks out a laugh. He gives Merlin a long, considering look.

"There's something about you," he says ponderously, letting his tail flick round to skim across Merlin's cheek. "I can't quite put my finger on it."

"Well, keep your fingers… and tail… to yourself."

Suddenly Arthur is smiling in a very suggestive manner.

"Are you sure that's what you want?"

The tail isn't so much skimming Merlin's cheek anymore as it is caressing it. Merlin feels an odd kind of shiver go through him that has nothing to do with the three-headed dog growling at him across the way.

Satan's son is… sort of hot?

And not just in the temperature sense, although the rapidly encroaching lava is getting rather toasty come to think of it…

Merlin squirms and then suddenly the pressure holding him down is gone.

He jumps to his feet and Arthur gives him a grin that only be described as filthy.

"I'll be seeing you, Merlin," he says, and his tongue darts out to lick his lips for a brief moment.

Then he vanishes.

None of that encounter should have been arousing. And yet…

Well, no-one ever said Merlin made good decisions. He had ended up in hell, after all.

He absently-mindedly gives Cerberus a pat on the head(s) and resolves to put Arthur out of his mind. He'll probably never see him again anyway.

And yet when he leaves the welcome building the next morning, he spots Arthur leaning on a wall outside, casually inspecting his fingernails.

"Registration go alright?" Arthur says.

"The hot wax torture was okay, but I could have done without that session on the rack," Merlin says, flexing his sore muscles. "I'm lanky enough as it is."

Arthur laughs.

"Least it's out of the way now. Where have they put you?"

"Eighth Circle," Merlin says, then answers Arthur's curious look. "Sorcerer."

"Oh, you're over in Bolgia Four? That one's actually pretty chill now. My dad used to have this, like, thing about sorcerers and it was sort of gruesome over there, but he's mellowed a lot. If you go down and get your head twisted at least once a day, you should be free to do what you like the rest of the time."

He gives Merlin an appraising look.

"I had you pegged as one of the sodomites."

"Ah well, I am that too, but I guess cross-classification might get a little complicated down here," Merlin says with a slightly flirtatious wink.

And when exactly did he start flirting with the Prince of Hell? How could that possibly end well?

He tries to change the subject.

"By the way you should really have a word with your dad on that topic. Confining sodomites to hell is pretty old fashioned, don't you think?"

Arthur laughs.

"They're not here because they're sinners! My dad never hated sodomites; he just knew they threw the best parties. The Inner Ring on Seventh is nicknamed Fire Island, for God's sake. Which is appropriate since, you know, it's mostly on fire."

Merlin sniggers.

"I'll have to pay a visit. If I can find it, this place is pretty badly signposted."

"You need a proper tour," Arthur says decisively.

"You offering?"

Arthur raises one elegant eyebrow and Merlin hates how it makes his knees go a little weak.

"Why not? Let's see. I've got the Gluttony Circle pot-luck at four, I could meet you around seven? Lust Circle's having an orgy tonight, which isn't, you know, unusual for them; but we could go check it out."

Yes, Merlin likes the idea of going to an orgy with Arthur. He likes it a lot.

"In the meantime, you should just explore. Limbo's worth seeing, even if they are all a bunch of squares. Careful if you pass through the Fifth though, those guys are kind of touchy."

"Got it," Merlin says.

"Okay, I've gotta go play some Nickelback to torture the hypocrites. Hey, in a couple of decades my dad says we can get the real live band down here! That's really gonna piss everyone off."

Arthur winks and vanishes into thin air, leaving a cloud of red smoke behind him.

Merlin lets out a long breath, his pants suddenly feeling uncomfortably tight.

"I've gotta learn how to do that."

The orgy turns out to be very diverting indeed. Merlin spots Cleopatra right away, doing some sort of complicated striptease, and he's pretty sure that's Helen of Troy in the corner making out with Dido of Carthage. Then he gets distracted by the sight of Achilles and Patroclus enthusiastically rutting against the wall, and pauses to watch a while.

"Don't stare too long; Achilles tends to get a bit possessive of his boyfriend."

Merlin turns to see Arthur looking resplendent in… well, it's a glorified codpiece essentially. And nothing else.

He's aware his mouth is hanging open in a rather uncouth manner, but politeness is probably not much of a virtue round these parts.

"You're overdressed," Arthur says critically.

"I could take my shirt off-" Merlin begins and Arthur clicks his fingers.

"Or you could just make my clothes disappear, that's fine too," Merlin says weakly, halfway between horrified and hard as a rock.

"So," Arthur says, and Merlin looks up to find him inches away. "Have you ever had sex with a Prince?"

He shakes his head, and jumps as Arthur's forked tail wraps itself around his cock.

"Would you like to?"

"God, yes," Merlin says quickly.

"I think you mean 'Satan yes'," Arthur says, and nips at Merlin's mouth with new-made fangs.

Merlin thinks they draw a crowd of their own after a while, and he's sure he hears Cleopatra make some pretty salty comments in the background, but mostly his head is full of how good Arthur's skin feels against his, the warm slide of their bodies together, the positively sinful things Arthur can do with his tail.

Arthur must teleport them at some point because he wakes up on a ridiculously plush bed in a surprisingly minimalist room, head resting on Arthur's bare chest.

"I thought your bedroom would be all chains and whips," he mumbles sleepily.

"I hate clutter. Plus, what are dungeons for?" Arthur says, carding his fingers through Merlin's hair.

"S'nice," Merlin says, snuggling down into the red satin sheets.

"Stay, if you want."

"What?"

"My father's been pestering me to get a consort for the last millennia. Do me a favour and get him off my back?"

"A consort?" Merlin says, slightly taken aback.

"Yeah, you know. Someone to bolster up my evil schemes. Work logistics for the more complicated torture stuff. Be my date at the Inner Circle prom and all that."

"Do I get to torture people?" Merlin asks curiously.

"Oh sure, go nuts. The most important thing as a consort is to have fun and be yourself," Arthur says enthusiastically.

Merlin considers for all of three and a half seconds.

"Sign me up!"

Arthur beams at him.

"Excellent! Normally I'd have Mephistopheles pop by with the blood contract but we could just take a short cut and seal the deal with an exchange of body fluids."

"Which body flu- argh!"

Demons have a lot of stamina, Merlin reflects, nearly ten rounds later.

He's not complaining, though. Not a chance in hell.