True Nature

A/N This is a first attempt at Omegaverse (which I've only started reading in the last couple of weeks) so I'd really appreciate any feedback. Thanks for reading.

John Watson had no shame about his biology but no reverence for it either. He was an omega, he got on with it, end of story.

Heat suppressants were mandatory during combat tours in the army and he had kept using them after his discharge but every now and then he let a few heats happen naturally. Not so many that his whole life was dictated by them but enough to satisfy himself that his demanding diva of an omega reproductive system was still working because one day soon he just might want to bond, have a family.

Today though was not that day. He was methodically packing a bag to go and spend this heat as he had the last. With Lieutenant Billy Scott, an unbonded alpha he knew from his last tour. A younger man, who had no interest in bonding until his career was established and was more than keen to help John out with his heats. It was a good arrangement, they spent a few days in his flat shagging like rabbits and then parted with a hug. It was simple, honest. It wasn't what he wanted to do forever but for now it did him very well thank you very much.

Things generally had taken a turn for the better in the last few months following a rough spell after he left the army. He was getting regular locum work and was in a decent enough flat for the rent he was paying. Then there was his flatmate. The eccentric 'consulting detective' and his work kept John's life interesting, that is to say, just dangerous enough. More than that, Sherlock seemed to find sex, procreation and therefore John's omega status unspeakably dull - which made things easier.

Packing complete, John wrote a note to Sherlock, treble underlining BUY MILK, before sticking it to the fridge. He picked up his bag and keys and he headed for the door just as it was flung open. Sherlock looked like he'd been dragged through a hedge, literally. His precious coat was filthy and fragments of dead leaves were tangled in his hair.

' John, thought you'd be gone. You didn't miss much, barely a three.'

' You're bleeding. What happened?'

'Just bushes.' He said dismissively, shedding his coat and suit jacket to check for damage.

'Bushes with Stanley knives? This one looks like it needs stitches.' John had gone into medical mode, heat almost forgotten, as he gently prodded around a nasty gash on Sherlock's forearm.

'I'll get my kit and patch you up.' John dropped his bag at the door.

'Don't you need to...I mean, aren't you in a hurry ..?' Sherlock broke off awkwardly - actually blushing.

'Don't you start going all embarrassed on me. I get enough of that at work. Treating me like some delicate flower. I've got time.' John said, opening his medical bag.

'Besides it's not so bad the way I do it- heat. Getting shagged silly for a few days by a good looking soldier- much better than silicone.' He looked for a scandalized reaction from the detective as he laid out supplies, but his voice seemed to have barely registered-as usual. John knew he was more forthright than most omegas who were brought up to be pretty much ashamed of their heats.

He had Sherlock sit on a dining chair beside him. The injured arm resting on the table as he cleaned it. It wasn't as bad as he'd thought once the mud was gone and all that was needed was a proper clean and a bandage. As he worked he became aware of a faint scent, a scent that had to be from the last time Lestrade visited. The alpha policeman smelled lovely and John put it down to his heat because he'd never really noticed Lestrade in that way before.

It took a further few seconds for John to realise two things. One, Lestrade hadn't been to the flat in weeks and two the scent got stronger the more he leaned into Sherlock, which he was doing unconsciously, his head far closer than medically necessary to Sherlock's chest.

All at once John had kicked away his chair and backed into the wall, raw instinct moving him quickly. He stared at the detective, fingers curling into the paintwork.

'I'm not what you might call active.' Sherlock said calmly, standing and carefully moving towards the window. He appeared to be giving the, now frightened, omega space and access to the door. John made no attempt to leave.

He had long assumed the detective was a beta, an unusually arrogant one, but a beta nonetheless. They had never talked about it, but he'd had no scent, until now.

'How can you be around me and not be...you know.' John ran his eyes down Sherlock's body but there was no sign of arousal.

'Suppressant, I developed it myself. I missed an injection yesterday. The side effects are rather unpleasant, nausea and so on. I sometimes miss a dose, while I'm working. I don't feel it myself but the lower levels are obviously affecting my scent, especially with your approaching heat.' Sherlock stayed perfectly still.

' It's faint but-getting stronger.' John said chewing his lip but relaxing slightly. A hostile alpha would have cornered him by now- well, they would have tried. He'd seen off more than his fair share in the army.

'I assure you, you are having no effect on me. Can we sit?' Sherlock gestured towards the fireplace. They skirted the edges of the room before sitting in their respective chairs.

'Why would you want to suppress being an alpha?' John could not understand this for a second. He had made peace with his own body's complications-but to be an alpha. The control, dominance, a whole society that revolved around your need to breed.

Sherlock sat back in his chair, his body language neutral. ' In a word- distraction. Trying to think with the constant bombardment of smell- it's like trying to read in a crowded train carriage with a dozen conversations going on around you. Who's just had a heat, who's about to have one-dull. I don't know how other alphas stand it- or omegas for that matter. I decided quite young I'd rather have a clear head.'

'That simple?' John laughed in astonishment.

'You don't feel any urge-at all?'

The detective sighed as if the whole topic bored him. 'I get erections occasionally if that's what you mean.'

That had not been what John meant. Now though, he was imagining how Sherlock would look, arousal darkening his striking eyes and staining his skin. That ghost of delicious scent at full strength. It was all he could do not to cross the room and climb into the alpha' s lap. His traitorous omega body ready to lie down and open up- any urgency to leave gone.

Hormones John just hormones.

He became aware of Sherlock studying him closely and he suddenly realised this heat was much further along than he thought, no doubt progressed by his flatmate's pheromones. His skin prickled and burned and he could feel the beginnings of an empty ache, almost like a hunger, that he knew would scarcely leave him for days.

'It probably is time for you to go. I'll call you a cab.' The detective stood and John became aware that he was standing too, a few scant feet from his flatmate.

John's limbs would barely cooperate as Sherlock saw him downstairs and into the cab. He let the omega rest against his shoulder as he chaperoned him across the city.

It would only be a few days later, as John let the blissful steam of a hot shower clear the last chemical vestiges of heat from his brain that he would remember. Sherlock. The alpha' s slim body trapped between John and the wall of the deserted lobby in Billy Scott's building. John couldn't remember how they'd got there or what he said, typical heat stuff probably, telling Sherlock how wet he was, begging to be knotted- now. He did remember the look of utter panic on Sherlock's face before he firmly took John's arm and led him to the other alpha' s door.

Thanks again for reading. I think this will be about five chapters. I've got 2 pretty much done so hopefully I will post this on Friday.