Title: Fast Learner
Author: ISJ
Pairing: Aziraphale/Crowley
Fandom: Good Omens
Rating: NC-17
Disclaimer: Good Omens belongs to the geniuses known as Terry Pratchett and Neil Gaiman.
Note: First Good Omens fic, and I had to go and blow my GO fic virginity on a PWP. I am trying to muster disappointment with myself?
Summary: Aziraphale's powers of observation prove most useful against his associate.

***

Crowley hadn't been paying that much attention, honestly. He'd gotten into the wine and into an ancient book of erotica and settled down to hissing contentedly every few pages and forgetting almost entirely about the angel at the counter ten feet away. After the initial affronted glances at the demon for so shamelessly using a valuable historical text for his own kicks (actually, Crowley had argued, mostly he'd been using it for a few laughs; humans always thought themselves so clever in the field of sexual perversion, when in fact it was maybe the one area of deviancy in which demons could still give the mudbags a run for their money), Aziraphale had given up with an offended sniff and sunk, brooding, into a text of his own, considerably drier and more sanctimoniously dull, just out of spite.

At some point Crowley was half-aware of the angel shuffling out of the room, then back in a moment later, but he was at a particularly laughable bit of contortionist lunacy and so didn't notice the reason for Aziraphale's brief absence.

Then, a few minutes later, he looked up from a graphic illustration at a sudden strange sound from the counter. If he had been remotely capable of conceiving the adjective in Aziraphale's dusty bookshop, he would have been tempted to say it was a wet sound.

The demon's eyes grew very wide, very rapidly.

Now, he knew, in a vague, not-knowing-he-knew-it way—the way he knew about Regency snuffboxes and most of Aziraphale's other affinities—that the angel was partial to chocolate. He did not have what the humans called a "sweet tooth," but chocolate was something altogether different, a whole taste phenomenon with which the angel had been intimately acquainted since the substance's introduction in Europe, if not before. While Aziraphale might pass up on a tiramisu or custard or even a decent biscuit, he could smell chocolate with a supernatural sense seemingly from miles away, and got a weird gleam in his eye whenever given the opportunity to indulge in a fine chocolate silk pie or rich dark chocolate torte or fudge cake or chocolate-covered strawberries…

Crowley unconsciously licked his lips. Because, if he'd been paying attention, he would have noticed that, after leaving the front room of the shop, Aziraphale had returned with a small canister and spoon in hand. If he had been paying attention, he would have noticed that it was a can of chocolate cake frosting. And, if he had been paying attention, especially as raptly as he was paying attention now, he would have seen Aziraphale innocently peel back the tinfoil lining of the can and return to reading his book while absently spooning out a dollop of frosting.

And proceeding to lick it.

Lick it. Like a cat. Like a…a blonde-haired, blue-eyed, cherubic, chocolate-addicted kitten, intent on savoring every single second of bliss to be found on that spoon. Slo-o-o-owly, and with a happy little facial expression that suggested only barely-stifled noises of delight.

Crowley felt he should be disgusted, but something about the movement of those plump lips over the slowly-disintegrating lump of chocolate, occasional flashes of tongue pink against the brown, threw a large and quite solid monkey wrench into the demon's mental gears, and he just sat there in the wingback he'd manifested, frozen, staring, for some reason unable to look away.

He tried going back to his book, but as he tore his eyes away from the chocolate-suckling angel, he was met with the illustration he'd been sniggering at not two minutes ago, of a rambunctious-looking orgy (as rambunctious-looking as any Gothic figure-paintings ever got, anyway) arrayed around a pair of central figures twisted into a most elaborate dance-like mutual fellatio. Quite beautiful; also quite impossible.

For the normal human spine.

Crowley felt his entire body save for one appendage go absolutely numb and he forgot to breathe for a whole minute. His eyes slid, guiltily, against his own will, back to Aziraphale, who was just leaving off reading for a second to refill his spoon.

The demon watched, helpless, as the angel put the entire bowl of the spoon into his mouth, closed his lips over it delicately, and sucked.

Ngk! Crowley thought, but dared not emit it out loud. He jerked his head back to the book in his lap—er, the less time spent thinking about his lap, the better, actually—and flipped pages at random til he finally found a pair that were all text, no more troublesome illustrations. He pretended to read. Aziraphale let out a little sound that made Crowley wince and hunch farther into the chair. His eyes were unfocused and his breathing, resumed at some point, was rapid and irregular.

For some confounded reason, Crowley's eyes moved of their own volition, entirely independent of the brain, I swear, back in the direction of the storefront counter, he trying his noblest to wrench them away and somehow failing. Aziraphale was bent over his book, totally absorbed, ringlets of hair falling over his forehead and ears, while his left arm was tucked under him and his right elbow was propped on the counter. The silver end of the spoon protruded from his o-shaped lips, and he took the handle in his right hand and drew the utensil out of his mouth nearly all the way, then slid it back in. Then he repeated the action. Out. In. Out slowly, agonizingly slowly, sucking off a tiny bit of frosting on each pass, then back in quickly to have another go.

After a small eternity of the angel eating rapturously and the demon watching enthralled, Aziraphale's eyes slid closed and he began to work the spoon with his tongue inside his mouth, getting off all the last delicious traces. Crowley's jaw fell and it was a moment before he realized it had actually come unhinged on the way down. He snapped it shut quickly.

The spoon was withdrawn, licked completely clean, from Aziraphale's mouth with a tiny smacking of lips, and the angel swallowed thickly.

And raised his big blue eyes to find Crowley staring straight back.

The demon shot up out of the chair as if launched, the heavy book tumbling onto the floor. Aziraphale winced first and then looked exasperated.

"Crowley, really!"

The demon, unthinking, stooped to gather up the forgotten book and snap it shut. He adjusted his tie and smoothed back his hair in a way he hoped looked very collected and cool, and in fact looked highly agitated, which is what it was. Thunking the volume onto a stack of unshelved newcomers, Crowley stepped briskly toward the front door of the shop.

"Well, it was fabulous, Aziraphale. I think it'll be a big seller…or would be if you ever sold it. Or, well…anything. But, anyway, the drinks were excellent, and let's not wait another fifteen years to do it again, eh?" He was edging resolutely toward the door, not so much trying not to appear rude as having a brutal internal struggle between one end of his body and the other. The upper half was a klaxon telling him to get out of there while he had dignity and sanity still relatively intact, and the lower was so loath to leave now, when things could just be getting good that the legs seemed to be deliberately sabotaging themselves against all further movement. The effect was to make a cold sweat break out on Crowley's forehead while a hot sweat beaded his legs underneath his trousers, to say nothing of the fact that he couldn't seem to recall exactly how to get out the front door…

The angel was frowning concernedly. "My dear boy, are you quite all right? You look positively unwell." He laid his little silver spoon down with a soft click on the counter and came around to closer inspect his associate.

Crowley fell back against the door, petrified. His eyes narrowly followed Aziraphale's movements, which didn't seem to get the hint that his proximity was really quite unsettling the demon until he was already too close for comfort.

The angel's frown was half worried, half annoyed, and turned his lips into the suggestion of a pout. Crowley cringed.

"Really, Crowley, what's the matter with you? You're going in quite a hurry. Not to mention you look like you're preparing yourself for a smiting."

Crowley's left hand groped for the doorknob while the right curled clawlike around the jamb, unwilling to be torn from the spot.

"I…I am feeling a bit…off…" the demon offered lamely, though his voice was convincingly hoarse. "Think I'll just go back to the flat."

"Well, really, do you think you should be driving like this? Perhaps you'd better have a lie down for awhile…" The angel instinctively drew closer to examine the weird glitter that had suddenly appeared in Crowley's eyes. "I think your pupils may be dilated, dear; you haven't hit your head or anything?"

That close, Crowley could smell the lingering sweetness of chocolate on Aziraphale's breath.

His yellow eyes flashed once, and he attacked.

Crowley had less discerning tastes in sweets than Aziraphale did. He wasn't much for sweet things in general but didn't really see the point in passing up a perfectly good danish just because he might get crème brulee later. So, not really less discerning. Just less patient.

Far, far less patient.

And, as far as he was concerned, the chocolate he thoroughly sucked off of Aziraphale's startled tongue was the most delicious dessert he'd had in a very long time.

"Angel," he growled—even as a demon, he was not in the habit of growling, as such, and commended himself on a very convincing performance—"I don't know…" Kiss. "…where you learned to…" Lick, bite. "…do that stuff with your tongue…" Suck, kiss again.

The angel was not, had never been since the Arrangement had more or less altered itself that fateful Sunday, all that fond of molestation without warning. He did have some sense of propriety, after all; it was just rude to suddenly jump one's significant other and skip all the ritual niceties. "Really, my dear," he had once thwarted Crowley when the demon had tried to conveniently forget Aziraphale's desire for a semblance of dignity about the whole affair. "You do take all the fun out of it when you go so fast it's over before it starts."

Assumably because of this, Aziraphale had flailed bravely for about the first twenty seconds, but Crowley's criminally talented mouth had reduced him to only a token sort of half-struggle. He gasped at Crowley's lips on his throat, and the demon chuckled lowly, congratulating himself on a temptation flawlessly executed.

What he missed was the little self-satisfied smile on the angelic face.

"Well, I did learn from the master, my dear," Aziraphale muttered huskily, hands finally giving up pretending and curling around to rub up and down sharp shoulderblades.

Crowley froze and lifted his head to stare wide-eyed into Aziraphale's smug, flushed face. Then he flashed his most impertinent grin—which was roughly equivalent to the impertinence of a housecat sitting next to an empty gilded cage with one feather stuck jauntily to its lower lip—and tore open the front of Aziraphale's shirt.

"Ack! Crowley, that was one of my better shirts!"

"Mm-hm, and this is about to be one of your better fucks." He quirked his eyebrows as he stared up from where he'd halted his lips a millimeter from one blushed nipple. "D'you want the shirt back?" And then he poked out the tip of his tongue and traced a perfect circle around the nub of dark flesh, eyes fixed on the angel's face.

Aziraphale moaned and jerked Crowley's head against him.

The angel's clutching fingers remained curled tightly into Crowley's dark hair as the demon traversed the curves and hollows of Aziraphale's chest and stomach, on a one-way trip downward. But at the last possible moment, as Crowley was reaching up a finger to flick Aziraphale's trouser button into orbit, the angel yanked the head up mercilessly, earning a yelp and much gnashing of teeth, and shoved the demon backward. Crowley hit the edge of the counter with an "Oof!" and shook his head, wincing and massaging his crown.

"Now, now, I rather like the supernatural avoidance of male-pattern baldness, angel. Let's try not to rip out my entire scalp next time, yes?"

Something molten flashed in Aziraphale's eyes as he advanced and the demon's mouth snapped suddenly shut. His fingers curled on the edge of the countertop.

"I would say 'Suck it up, Crowley,'" the angel murmured into the other's ear as he locked his hands under the swells of Crowley's thighs and bodily hoisted him up onto the counter. "But I think that may be taking the tasteless humor a bit too far."

The counter was cool through Crowley's trousers, and he shivered, eyeing Aziraphale with predatory interest.

"Mm, I dunno about tasteless," he leered, running his long tongue over his bottom lip. A hint of cocoa still clung there, and he sucked the lip into his mouth to clean every last trace off.

The added benefit was the coy expression this made out of his face. Aziraphale's eyes sparked again, and he pinched both Crowley's nipples simultaneously through his shirt right before it disappeared. The demon gasped and his fingers scrabbled against the smooth countertop, finding no purchase.

"We already know about the weird things your tongue can do, serpent," the angel hissed, darting his tongue into Crowley's navel once, twice. The demon squirmed. Suddenly his pants were unbuttoned, and Aziraphale's hand was there.

"Why don't we find out how well I've been paying attention?"

All component parts of Crowley were unanimously in favor of this.

Especially that very human part which, honestly, hadn't really taken that much effort at all. In fact it had seemed quite eager upon first awakening some several hundred years ago. Though that was nothing compared to what it was now.

Aziraphale seemed taken aback by how hard Crowley had gotten in so short a space of time. The angel swallowed as he looked at it, his face unreadable and his eyes huge and translucent under his wispy hair.

And then time slowed to a crawl for Crowley as that golden head bent to swallow him up.

"Good Go—rmphnng…mn." The first two fingers of Aziraphale's left hand had made their way up Crowley's chest to lock onto his face and thrust themselves past his lips. He whimpered and did a positively fascinating job of emulating Aziraphale's motions down below, licking and gently suckling, nipping, dragging them in and out and in.

The angel moaned. Then Crowley did. Then they sort of lost track of who was moaning and when, only Crowley knew that it felt so. Fucking. Incredible.

It appeared that Aziraphale had, indeed, been paying quite good attention to Crowley's tongue tricks all these millennia. He certainly must have picked up something useful from somewhere, because Crowley had utterly exhausted English and begun delving deep into Arabic as the angel made his mind and body melt like so much cake frosting.

No, wait…That was actual cake frosting…

The Arabic ran out and something much, much older and with far more sibilants took its place. Crowley had only impressions of the silver spoon and the tin of frosting flashing in and out of his rapidly-deteriorating line of vision, while the wet heat of his associate's mouth never really disappeared, or in any case not for long. Crowley's errant yellow eyes, again, entirely of their own accord, he felt sure, turned downward, though the sight of Aziraphale's lapping, stroking tongue and the sensations it was inspiring in Crowley's body seemed oddly detached from one another, out of sync.

Probably because just then the angel, big blue eyes turned up to gauge his progress on the demon's face, closed his mouth around Crowley and gave a brief, hard suck, and Crowley came fiercely, light exploding against dark both in front of his eyes and behind them.

When his mind came back, Crowley had the distinct and pervasive feeling of having no bones whatsoever, and he wanted to grin stupidly and simply slither backwards off the countertop and never move again. He probably would have, too, had Aziraphale not still had a firm grip on his bony hips while he licked off the last traces of what his tomfooling tongue was capable of.

The angel swallowed and delicately removed a fleck of chocolate from the corner of his mouth with a meticulous fingertip as he straightened. His eyes were still luminescent, and his lips swollen and parted, and Crowley's spent body pricked itself awake.

"How was that, dear?" Yessss, voice much hussskier than it should be…

"You've, erm, most definitely been taking notes, angel. Bravo, quite, ah, quite studious of you." The impertinent grin was firmly back in place.

"Studious."

"Yes. Quite."

"Aha. Well, good, I have been practicing, you know." Aziraphale smoothed at his somewhat tousled hair and picked up the half-empty canister of chocolate and the spoon. He scooped out another modest spoonful and popped it back into his mouth as he left Crowley's side and wandered off toward the stairs.

Gathering himself more or less together, Crowley hopped off the counter.

"Aziraphale?"

"Mm?"

"Might I have a taste?"

"A taste of what, my dear?" the angel replied, ascending the stairs with his chocolate and disappearing around the corner.

The demon prowled after him, licking his lips as he went.

***