To calm his mind

Apparently I am still not over Good Omens and Aziraphale/Crowley. In fact, I am waist-deep in their quagmire - no regrets though, I am loving it. Here comes something that has been sitting on my proverbial desk for quite some time now, and I finally made the time to write it. Enjoy!
Warning: explicit sexual content and the like

You know that feeling when you are restless all day for no apparent reason and can't seem to do anything about it? When your skin crawls and your leg keeps bouncing and your eyes roam the room as if looking for the reason for or the solution to your strange mood? Well, Aziraphale has been feeling like that all day. And he didn't fancy feeling like that at all.
He tried to keep his mind occupied by re-organising his restoration literature bookshelves but it was decidedly a poor attempt - he just grew frustrated with himself and that made him even more restless. He was about to give in to the temptation of closing up early, seeing there were currently no customers around and he preferred it that way anyways, when the bell above the shop's door jingled.
'Excuse me, dear, but we are closing early today, in fact, I was just about to...' he started as he was walking from the back of his shop towards the unwanted newcomer. 'Oh, it's you!'
Crowley, sauntering around the front sections of the shop, grinned at the angel's surprised but pleased exclamation. Instead of coming up with something cool and witty, as he was originally planning on doing, he simply strode up to Aziraphale and hugged him.
'Hey' he whispered in the angel's blond curls. Aziraphale clung to him and buried his nose into Crowley's jacket. 'What is it, angel?'
As there was no answer, Crowley began to get worried.
'Angel, you okay? You seem.... a bit off' he suggested meekly, not wanting to offend his angel.
'I am feeling a bit off, to be honest, my dear, only I can't really put my finger on the why' admitted Aziraphale softly, finally letting his guards down and relaxing into Crowley's embrace.
'Oh, 'tsokay, angel, we'll make you feel better in no time' reassured him the demon with an encouraging little smile and Aziraphale couldn't help but believe him. 'You wanna go to some restaurant? What about that new sushi place you wanted to try? Or maybe some Mexican? Chinese? Turkish? Indian? The Ritz again?'
'No, darling, really, I just want to stay in tonight' sighed Aziraphale and glanced uncertainly at Crowley. 'Would that be acceptable to you too?'
'Are you kiddin', angel? Anything you want, you know that.'
'Thank you, my dear.'
And with that, Aziraphale was ushered in the direction of his back room and was sitting on the couch before he could have blinked. Crowley snapped his fingers for a tea - Aziraphale liked to make it the human way as he found the ritual soothing but a demon, even if said demon was only Crowley, the least demonic of them all, would still never refrain from a miracle when it came to making a fucking cup of hot liquid.
'You sell anything today?' asked Crowley as a way of distraction.
'Luckily, no' replied Aziraphale with a slight smile and sipped his tea.
'Any fun old ladies or insubordinate youngsters in?'
'Alas, no, not today'
'Hmm. Stray cats?'
'Not anywhere near my shop'
'Hmm.'
'Don't sound so disappointed, my dear' chided Aziraphale, now definitely smiling. 'And what kind of mischief have you been up to?'
'Oh, just the usual stuff. Annoying random people at the park, causing traffic jams in the morning, flat tires for some politicians, some dog poop on a few irritating people's shoes, the like' shrugged Crowley, knowing fully well that his angel was going to secretly approve of all his minor wrongdoings. He always did.
They lapsed into a comfortable silence and as Crowley snuggled close to Aziraphale who was still sipping his tea, he could feel the angel loosening up a bit. As the cup emptied and was put aside, Aziraphale took one of Crowley's hands in his and absentmindedly started drawing small circles on it with his thumbs.
'Feelin' better now?' mumbled Crowley against the angel's neck, which sent shivers through Aziraphale. He bit his lip and nodded. Crowley's closeness and the tender strokes of the demon's palm against his shoulder got him relaxed and curiously aroused at the same time. He was on the edge of getting very much sexual thoughts about how the evening could continue for them but he stopped himself. He wanted to get back to his usual place of mind and leave all his uneasiness behind before jumping on Crowley like some kind of carnal animal. Which he had admittedly done several times but always feeling very much himself, not like this.
Crowley must have felt his uncertainty and growing arousal because he placed a few feather-like kisses on his neck and tilted his head to kiss him on the lips. Deeply. Passionately.
And just like that, they were snogging on the couch and Aziraphale's head was filled with steamy images. He broke the kiss.
'No, my dear, not yet. Not like this' he pleaded softly, shaking his head.
'Oy, angel, come on, you know it will help' murmured Crowley and went back to kissing Aziraphale senseless.
They were naked and slowly rutting against each other in no time, when Aziraphale stopped them again.
'No, Crowley, please. I just... I can't' he whined. He was already rock hard and he wanted his orgasm and wanted it soon but something just felt not right.
And then he understood.
'My dear, I'm afraid I've been.... fantasizing. And I was not planning on telling you, obviously, but now I feel like I have been cheating on you and I just have to explain myself' he stuttered, face gone completely red, not because of his openness and honestly, that was nothing new in their relationship, but because of the nature of his fantasies.
'Fanta-wot? You've been fantasizing? Wow, angel, that's... what were they about, then?' asked Crowley with his eyebrows raised so high they almost disappeared in his hairline. He did not ask out loud who it was about. Cheating on me?
'They, uhm... you.... oh, my dear, this is really quite embarrassing' mumbled Aziraphale and buried his face in his hands.
'Come on now, angel, how could anything be embarrassing between us?' asked Crowley tentatively, and his soft tone made Aziraphale lower his hands.
'No, you are right, my dear. Of course. It'j just that... you had me bound. In my fantasy. While we were having intercourse' he explained in a hushed voice, face still flaming red.
Crowley's eyebrows nearly popped off his forehead.
'You are into bondage?' he asked incredulously, big yellow eyes blown wide. Aziraphale shyly shrugged. 'Okay, we can work with that. I guess.'
'But I don't want to make you do anything you are not comfortable with, Crowley' said the angel in haste.
'You are not' whispered Crowley and placed a soft kiss on his lips. 'I wanna put my own twist into it, if you'd let me?' As Aziraphale nodded enthusiastically, he added 'but tell me to stop if anything feels too much or even a bit uncomfortable, alright?'
'Alright, my dear.'
'Love you, angel' murmured Crowley as he gently made Aziraphale sit up on the couch and kissed his forehead. 'Ready?'
At the angel's nod, he started shifting and the next moment there was a snake staring up at a bewildered Aziraphale. It tilted its head to the side, as if asking for permission. With only the briefest second of hesitation, he got it.
Crowley slithered onto Aziraphale's lap, circled his wrists and pulled himself tighter around them. There was a surprised gasp from the angel and his arousal twitched. Crowley waited for a few seconds, but when Aziraphale did not stop him, he flicked his forked tongue against his soft belly and slowly, sensuously stroked his tail up the angel's inner thigh and over his balls. Aziraphale moaned and the throaty voice made Crowley's scales itch in anticipation.
Still moving slowly, giving Aziraphale the choice of stopping him anytime he wanted, Crowley moved his tail up around the angel's cock and circled its base, tightening his grip carefully. At this, Aziraphale whined and thrust his hips upwards, giving Crowley the green light.
Tail gripping firmly the base of the angel's erection, Crowley moved his head to those gorgeous tight balls and started licking his way up over them. The small gasps and moans told him exactly just how much his angel enjoyed it.
Time to tune it up a little then.
Tongue gliding over to the head of Aziraphale's straining erection, he started licking pre-cum from his angels cock and, had he still been in his human corporation, he would have come right then and there form its exquisite taste. Flicking his forked tongue around the broad head over and over again, faster and faster, he could feel the angel's wrists twisting in his hold, but not nearly strong enough to actually indicate wanting to get free. Aziraphale was right on the edge, pleading him to make him come, to go faster - so that was exactly what he did; tail gripping and starting to pump, tongue licking, he teased Aziraphale's erection with such intensity that the angel screamed his name as he came. It was the most pleasing sound Crowley has ever heard.
He made sure to lick all the cum from the angel's thighs and stomach, fluttering tongue tickling and calming him down after the orgasm. As Aziraphale was opening his dazed eyes after the intense pleasure he had just experienced, he saw Crowley shifting back into his human form.
'Thank you, my dear, that was... astounding' he sighed happily as the demon slid up close to embrace him.
'I should think so too, angel. Your taste is maddening' chuckled Crowley, burrowing into the heat of his angel's body. Turning into a snake always made him feel cold.
'May I reciprocate?' asked the angel after gathering himself properly, his hand already sneaking its way to Crowley's near-to-finish erection.
'Please, angel, do so' groaned Crowley, shivering, thrusting into the angel's incredibly hot palm. It took less than a dozen slow strokes for him to come all over his belly and Aziraphale's lap.
Basking in his post-orgasm glow he heard the angel snap his fingers and felt the cum disappear and a fluffy blanket appear around them.
'You know that fantasizing about me is not actually cheating on me, right, angel?' he asked as bits of their previous conversation popped into his mind.
He opened his eyes to see Aziraphale make a face and he laughed deep from his belly, which in turn made the angel beam at him as if he just pulled the stars from the sky.
'Still, I prefer you making me do things to you over you thinking about me doing those things to you' he added with a cheeky grin, and Aziraphale swatted at his arm.
'Oh, hush now, dear' he chided, smile audible in his voice, and that was the last thing Crowley heard before he fell asleep on his angel's chest.