A/N: Disclaimer: "Good Omens" and all affiliated suchlike belongs to Pratchett and Gaiman.

Hello and welcome to my first little stab at a GO fic. The idea bit me one morning, and after having quite a few people read it and assure me that it's not too bad, I figured I might as well post it. Crowley basically decides to do a little experimenting. I know that Crowley and Aziraphale are both provided with suitably human bodies from their respective bosses, but what they do with them is entirely their own idea, from what's on it to what's in it. I figured they probably wouldn't want to mess with the complicated bits when there was so much else going on. Well, this is the messing-with-complicated-bits part.

Warnings: Crowley/Aziraphale, suggestive thinking, and litter. Hope you enjoy this...I certainly did.

...

Humanity, Crowley decided, certainly was a precarious species.

It wasn't enough that the little carbon-based creatures had systems as fragile as withered leaves, no, but God had a sense of humor about them, too. Why else would simple day-to-day living be so...difficult?

Six thousand years based on Earth, living around humanity, had taken its toll on Crowley. He'd studied the things around him to fit in with them, but he hadn't really thought to be curious about them. It was that curiosity, coupled with a case of extreme boredom, that gave Crowley the idea to adopt an entirely correct human form for a few days. He'd always had the look down after a few trials [1] but only, as to be expected, in the most vital of areas. [2] Demons and Angels, as a rule, are genderless. But, if Crowley really was to be a true tempter, he ought to at least try to understand exactly what he had been tempting (or attempting to tempt) all these years.

With this alibi in place, a few hours of wrinkle-nosed study of an anatomy text and some instants of intense, tensed concentration left Crowley as human as a demon could get. He set out to see what a liver could really do with alcohol. But first, Crowley realized, he had to re-learn how to walk. And it was this that gave him his first real impression of the state of humanity.

When Aziraphale found out about Crowley's little experiment, the angel agreed to meet him in a nearby pub, if only to discern the truth for himself. Crowley was already well into Phase Two of his 'studies', entitled Get Royally Pissed. When he caught sight of Aziraphale, his lips quirked into a greeting smile. And then the look on the angel's face stirred something in Crowley he was absolutely sure he had not possessed before that afternoon. Holy...er...Unholy...uh...

Aziraphale came to his side before Crowley's mental tirade could decide whether to bless or curse. "Honestly, what do you plan to accomplish?" asked Aziraphale. The angel took a seat next to Crowley at the bar, gazing incredulously at the demon.

Crowley crossed his legs, bringing up images from the anatomy textbook of the exact and illustrated purpose of the spleen. "Absolutely nothing," countered Crowley, scrutinizing Aziraphale. Something was different about the angel, however minute. And then, he saw it. Crowley grinned. "Being around humanity for so long does things to you, doesn't it, angel? This is my way of dealing with it," said Crowley, and pointed to the lengthening fringe of fine hair dancing on Aziraphale's brow. "That appears to be yours."

Aziraphale had the decency to look affronted, blushing a bit. "If I don't pay attention to it all the time, my hair grows out. I haven't had the time to get it trimmed," he explained.

Crowley snorted, taking a moment to pause and pay attention to his digestive tract. He shut his eyes and decided perhaps the intricacies of a natural filtration system were beyond him at that moment. A soft grunt later, and his insides were again merely the opposite end of his outsides. [3] Without all of that mess, he could get comfortably drunk, though he no longer had an excuse for it. "Angel, you're...an angel. Think it back into shape."

Aziraphale looked down at the bar a moment. "I think I may keep it long," said the angel. The sweet lines of his face were illuminated in dirty yellow lighting, highlighting the blush on his cheeks and the curl in his eyelashes. Crowley immediately decided he liked the shaggy look, once he got used to it. There were moments when 'shaggy' suited the angel. [4] "And anyway," continued Aziraphale, "this is less drastic than what you're doing."

"Why?" asked Crowley, putting his face on his hand. He was happily buzzed enough to still be coherent. In the background, his body was giving him a lesson on anatomy that left him bemused and inclined to let Aziraphale keep talking. "You've got a body that's supposed to be human, much as I do. I was practically putting the shoe on the right foot."

"My dear..." murmured Aziraphale, and then stopped speaking. He appeared to be at a loss for arguing, and that suited Crowley just fine. The pet name had always been a small sign of affection, all well and good in accordance with the Agreement. "My Dear" was simply like "Angel", "Crowley", or "Aziraphale". They were points of reference and nothing more. But the way Aziraphale had said it, and the way Crowley's body was responding, suddenly gave "My Dear" a lot more emphasis than those two syllables could hold. [5] Perhaps it was the alcohol, but he was definitely seeing Aziraphale in a new light.

An instant later, he'd sobered up and looked at the angel again. No, it wasn't the alcohol. He hadn't really expected it to be the alcohol, but it was a good try anyhow. He pitched some money onto the counter and left the pub, knowing Aziraphale would follow in his own time. As predicted, sensible brown shoes fell into step with Crowley's black boots. Aziraphale slid his bowler back on over his hair and settled into walking alongside Crowley. The demon reached up and, with one swift movement, batted the hat off of Aziraphale, catching it with his other hand. Aziraphale made a small noise of disdain, but Crowley held the hat behind his back and put his other hand in his jacket pocket. Aziraphale contented himself with leaving it in Crowley's care for that long.

Their feet led them to a familiar pond, and Aziraphale quickly went across the street to purchase some bread to pitch to the ducks. Crowley watched him go, and put the bowler in his lap. It was as good a place as any. Crowley sat and watched the ducks, who soon paddled swiftly toward him in recognition. Better instincts had been overrun by the gluttonous desire for a few bread scraps. When Aziraphale returned to his side, they clamored for position. The angel pitched pieces of stale bread into the mass of ducks, patting Crowley's shoulder when the waterfowl brawled over them. The demon grinned.

"So," said Aziraphale, sitting on the bench next to Crowley. "Have you had enough of humanity?"

Crowley looked over at the angel serenely pitching hunks of bread to the ducks. And his grin grew wry. "You should try it. It's a learning experience." Aziraphale nodded a little, murmuring in his throat. Crowley was overcome with an incredible urge to put his tongue in the angel's ear. Moreso, he wondered how he could get the angel to do it to him.

Well, Anthony J. Crowley was a demon, a tempter extraordinaire, skilled in the arts of sin and deceit. But Aziraphale was a little different, leagues different. Six thousand years with only one constant lends someone to understand that person better than anyone else. And the thoughts running from Crowley's groin in a hotline to his brain would certainly not sit well with the angel. Where Crowley ran by the Seven Deadly Sins, Aziraphale practically had a needlepoint of the Seven Heavenly Virtues on his wall. Worse, Crowley's brain cut in, inadvertently causing the angel to Fall after indecent consort with a demon would destroy Aziraphale. And Crowley, for all his supposed evil, wanted absolutely no harm to come to the angel.

However, years of chalking up minor victories over Aziraphale for Hell had given Crowley a certain way with words.

He leaned back on the bench, stretching his arms out on the backrest. His thumb came close enough to graze Aziraphale's neck. "I'm calling it research. You could too," suggested Crowley, watching Aziraphale throw bread to the ducks. "Part of being ... all there ... is fun."

Aziraphale exhaled sharply through his nose. "My dear, if you really think I'm going to go through the complicated mess of altering my body, you are sadly mistaken," said Aziraphale. In response, Crowley reached up and flicked the new length of hair at the nape of Aziraphale's neck.

"It's not hard," murmured Crowley. That second "My Dear" had only strengthened his resolve.

Aziraphale turned on him with a shocked, flushed look. "Are you trying to tempt...me, of all people?" asked the angel.

Crowley blinked rapidly, putting one hand to his chest and the other around Aziraphale. "Me? Why, angel, I'm insulted. That would...practically be doing good." He grinned like a snake. "It's not a sin to make an angel happy, is it?" asked Crowley.

Aziraphale frowned into the onslaught, staring into his reflection in Crowley's sunglasses. "Happy, I fear, is circumstantial."

Crowley edged closer to him on the bench, pressing their sides together and speaking inches away from Aziraphale's mouth. "You tell Heaven you're making a demon want to redeem himself. I tell Hell I'm tempting a holy creature. And you get to find out what it feels like to be a real boy," purred Crowley. "This isn't something one should go six thousand years without trying."

"Crowley," said Aziraphale, putting both hands on Crowley's shoulders and pushing. "Crowley, I can't lie to my superiors!"

Crowley shrugged and squeezed Aziraphale's shoulder. "It wouldn't be lying if you believed what I told you." He grinned. "I'll bless if you come with me. And you could put a positive spin on the whole experience. I haven't heard you tell me 'no' yet." Crowley leaned over and put his lips in the soft space between Aziraphale's eyebrows. He reached up and pulled off his sunglasses, leaving them beside him on the bench. Aziraphale's bowler still rested in his lap.

Aziraphale grabbed two fistfuls of Crowley's shirt and pushed him away, looking the demon dead in the eyes. "Crowley," chided Aziraphale. "First of all, we're in public. And secondly...secondly..." Crowley's bright eyes were trained on Aziraphale's mouth and the slow thumb tracing its way over Aziraphale's lips. The angel found it increasingly hard to talk under such attentions, quickly losing the second point to his argument. "...stop," he pleaded.

The smirk reached Crowley's eyes. "You're the one tempting me, angel," hissed the demon, "because this can't possibly all be my fault." Crowley removed Aziraphale's soft hands from his shirt, held the wrists together in his own hands, and caught Aziraphale's mouth with his own. Aziraphale sat shocked for a moment, unable to do anything except let Crowley have his way.

This was one of those explosive kisses like the touching of lightning and water, of flame and alcohol, of acid and base. To Aziraphale, Crowley tasted of soot and sin and all the disgusting, slimy things a mouth that stolidly refused to taste a curse word for six thousand years could revel in. Crowley was the delicious darkness, all lust and spices, hitherto off-limits to anything holy. To Crowley, Aziraphale tasted of sunlight and virtue and all of the wonderful soft sweetness he had left behind. Aziraphale was love and caring and everything beautiful on God's green earth, softer than clouds and hotter than Hell. Black crashed into white, meshing into a pleasant sort of sensual gray area utterly unfamiliar to the two extremes. The gray was wholeness, was the meeting of dark and fair, was the mud from which sprang forth all the carnal comforts humanity took for granted. When both pulled away to let the world return to some semblance of normal, the only thoughts ran along the lines of Let's do that one again...!

"We don't...have to be in public," slurred Crowley, giving himself a moment to realize just how fit and able his newly-augmented form really was. And how eager it was to prove itself.

"No," agreed Aziraphale, "we don't." He shook himself out of Crowley's grasp then, getting slowly to his feet and extending a hand to the demon on the park bench. "On the way, you're going to explain to me what being more human has to do with any of...of that." With those words, Aziraphale's pale cheeks took on a rosier tint.

Crowley grinned and took Aziraphale's hand, perching the bowler at a rakish angle atop the angel's head. As they walked, he slid his hand into the back pocket of Aziraphale's slacks. "Almost everything," answered Crowley, sliding his sunglasses back on over his nose.

They left an empty bag on the park bench.

...

[1] Including a rather humorous episode where Crowley learned the difference between cloth and flesh and where the two were really meant to connect. After an educational hour or so with Aziraphale, Crowley felt a little more confident about it. Arms and legs are foreign enough to serpents without using cloth to make a mystery of the region called 'torso' as well.

[2] Also known as Anything Outside of His Clothing.

[3] The outsides, however, he didn't have the forethought to tamper with. This would prove to make the afternoon much more eventful than it might previously have been.

[4] Humbleness was a prized virtue, apparently. Aziraphale, earlier on, had followed this idea to the letter, until Crowley managed to convince him that being groomed wasn't so much vanity as wanting to be able to function in a world where regular baths were growing extremely popular.

[5] This often happens with simple, open-ended phrases such as "I love you", "I'm sorry", and "It wasn't me".