Chapter Text
John dozed for hours lying on his side with Sherlock behind him, bodies touching only when one of them shifted. He felt just as he had felt that September when he was fifteen and his first full heat had come on. He had laid in his bed and stuck his fingers into himself and discovered, as every omega did, that it just didn't help. He'd whined, and ached, and in the middle of him something had spiralled tighter and tighter and tighter. He had felt that if he could just have someone inside him, just once, just for a moment, the whole thing would gloriously unspool and everything would be all right. And even as he'd felt it he'd hated himself for being so needy, so incomplete, so pathetic.
He'd gotten through that first full heat, emerging from his room after four days un-fucked, dry-skinned and exhausted and shaking, and after that he'd gone on the meds. But his family had made sure there wasn't an alpha anywhere near him all that time.
He had the advantages now of being older, more experienced, better in control of himself than a scared teenaged boy, but all that was cancelled out by the rich drugging smell of Sherlock all over him.
It was ramping up again, and before long his hips were tipping back against his will.
Sherlock, with a soft, "Mmm-- " wrapped a firm arm round him, shifted a bit to position himself, and pushed his cock smoothly into John.
John's head snapped back, his back arched, and he moaned in disbelief because it was so good, so unbelievably good. The best part, the worst part, was the lie his body had been telling him. It wasn't unspooling, it was all twisting tighter, agonizingly, stingingly, wonderfully tighter. Sherlock was pressed up against his bruises and he didn't even care.
Holding him close, Sherlock thrust slowly, gently into him, just slightly deeper each time. Sherlock, the greatest mind of his fucking generation, brilliant Sherlock, amazing frustrating fantastic Sherlock, who should have been racing across London, dissecting corpses, playing the violin, making forensic technicians cry, was here instead, reduced to a cock for John Watson to ride.
They'd been so good, the two of them, and now they were this, and he couldn't stop wanting it, couldn't stop loving it. It was too much. As he had at fifteen, John began, silently, to weep with the unfairness of biology.
Sherlock stilled. John felt Sherlock's face pressed to his hair. "I can . . . I can stop," he whispered, voice a bare rasp.
John did his best to wipe his face on the mattress. "No you can't. For one thing I'll kill you if you try it. We just -- we get through this."
Sherlock's hand shifted slowly, restlessly, along John's body. "There is an injectable medication, it only needs to be given weekly, you could administer it to me, so I won't get careless."
As if Sherlock being better about taking his meds would have avoided all this. "If you want, but that's not really . . . " Sherlock pressed in harder and John trailed off with a shivery breath.
"There's an operation too," Sherlock went on. "Keyhole surgery. Sever some of the nerves in the knot, cut off some connections in the epididmus. Apparently it can be done in less than an hour."
John felt as if he'd been kicked upward and surfaced suddenly from a warm lake of pleasure into cold air. "What? What the hell, Sherlock? This -- this is your idea of pillow-talk, is it? Threatening to castrate yourself?"
Sherlock held John's back hard against his chest. "It isn't a threat. It's an offer. A . . . compromise. So you -- so you won't leave." His voice was so low John felt it as much as heard it.
"Jesus, Sherlock, you're . . . you're actually completely unhinged, aren't you?" This was the most unsettling conversation he'd ever had, and that was ignoring the fact that it was happening while he was being sodomized by his lunatic flatmate. "I told you, I'm not going anywhere."
"That was before I did this to you."
Which was Sherlock getting it all wrong again, because this was something John was doing to Sherlock. And maybe that was enough to explain it, Sherlock was borderline mad at the best of times, and right now John's pheromones had pushed him straight out over the edge. "We get through this," John repeated, "and then we go on. And god damn it, Sherlock, you cannot make an offer like that."
"Clearly I can," Sherlock said, a hint of his old petulance in his voice. "I've never used it before, I never will again, and this is my choice."
It. Sherlock was talking about his reproductive system as if it were a fountain pen or a kitchen appliance he was considering giving to Oxfam. "Oh my god. That's -- You're thirty-five years old, Sherlock, and you're ready to mutilate yourself for life. Somewhere out there might be an omega you'd actually -- someone who you'd want to knot."
Sherlock started to move again, more urgently, pushing deep so John could feel the knot pressing at him each time.
John groaned unbelievingly. "You -- oh god -- you're not satisfied being bonkers by yourself, you're trying to drive me insane with you."
"That woman -- I told her her daughter's suicide was boring, and you -- you told me I was being cruel and you went for a walk -- " Sherlock's breathing was going ragged and he was grinding his hips.
"For god's sake, Sherlock, talk bollocks or fuck me, but stop bloody multitasking."
At least this time Sherlock kept moving. "And when I -- I woke up on the couch you'd put a blanket -- John! -- left me a cup of tea and -- and a defaced novel." Sherlock's hips stayed hard against John while his shoulders moved back as he hunched to bite at John's shoulder.
The bite, the sucking there, felt incredible. And then Sherlock bit hard at the back of his neck again and John felt his body go hot and stunned. It was one of those things alphas did to omegas that John had always sneered at, but it was so good to feel it, to feel Sherlock doing it to him.
Maybe all this really was just Sherlock's bizarre notion of pillow talk and John should stop trying to make sense of it.
John remembered the book. It had been one of his bids at fighting off Sherlock's boredom: he'd ripped out the last two chapters of a mystery novel and left it with a note promising to cede the kitchen table to science for a week if Sherlock figured out the murderer by the end of the day. They'd had a friendly sort of wrangle over whether the end of the day meant John's bedtime, midnight, or whenever Sherlock next felt like sleeping, and for a little while Sherlock had been mildly distracted. John had known better than to try the same thing the next time, but he'd filed the trick away to use again in a year or so as needed.
Oh.
"You want to -- " John's ability to speak was breaking up. "to neuter yourself so -- god, yes, like that -- so I stick around -- to do tricks for you?" He began to rock his hips helplessly.
Sherlock gave an anguished moan. He was shuddering. His cock was huge and perfect inside John.
John bucked back hard. "Idiot. You might -- god, don't stop -- you might meet an omega you want to spend the rest of your bloody life with someday."
Sherlock made a choked sound like agony, clamping his arm across John's chest, and those shudders felt like --
Those were sobs.
"Sherlock -- " John whispered, shocked into going still.
"I did," Sherlock whimpered, "I have. John --" And then with a long terrible groan he slammed his hips up.
The shock of the knot being forced into him and the shock of what Sherlock had said felt like the same thing: something too vast, too magnificent for him to survive.
The first time had been terrifying, Sherlock breaching him so brutally, the sudden blunt pain and horrible wrong shift as his insides were pushed into their new shape. He'd ejaculated until he couldn't any more, and it just went on and on and on, his insides clenching rhythmically and with every clench a wave like a sheet of electricity hitting his body, and it went on, and it went on, and he'd been sobbing helplessly for it to end as his body gave those last few sly flutters before finally, finally there was release and he'd gone boneless and heavy.
This time was just as overwhelming, but Sherlock had been gentler, taken longer, and John was ready. He felt rings of muscle stretch painfully and then clench, and heard Sherlock's wail, and felt himself coming -- the familiar buzz of pleasure centered on his cock, like every orgasm he'd ever had when life was normal. But there was also the slide and dull cramp as his anatomy shifted, and instead of fading the orgasm went on, it grew outward to cover the rest of his body, and his muscles were rippling and with every tiny movement he felt Sherlock's cock jerking inside him. Every time it rubbed across his prostate was like a gout of flame. His body seized over and over, crushing him with sweetness.
He could feel that Sherlock's hips were still helplessly trying to thrust against the hold that wouldn't let him shift a millimetre. He was repeating, "John, John," in a lost, desperate way, broken up by harsh grunts as if he were being stabbed.
After a long, long time that he knew could actually have been no more than three minutes -- unless he was some kind of medical anomaly -- the contractions of John's body went arrhythmic, spaced out and weakening. John rode out the end of it, easier this time, just floating over gentler and gentler waves of bliss until every muscle was soft and unstrung and he was lying still.
Sherlock was still clinging, flush against him.
"John -- " he rasped.
Oh for heaven's sake, could the man not come to a complete stop ever?
"Sleep," John mumbled.
"I -- "
"Hormones," John provided. "Talked a load of rubbish. Sleep now."
Sherlock tensed as if to argue, damn the man. Then the fight went out of him and he relaxed.
"Sleep now," John repeated, and heard his voice blurred probably beyond comprehensibility. "Need your energy in an hour or so."
Sherlock's hand stroked John's chest, sliding over slickness that was part sweat and part John's own thin ejaculate. It settled with his palm over John's left nipple, riding his inhale and exhale. "John." It was a dark, rough whisper that asked for no response but John's presence. John put his own hand over Sherlock's.
For now, for this little while, he was Sherlock's omega. Later, when they were both normally medicated again -- and nobody was at any point going to go under the scalpel thanks very much -- then they would be John and Sherlock again, just two odd blokes whose lives had inexplicably, irrevocably fused together. He'd run errands and hold his temper and try to keep Sherlock alive; he'd be what he'd been since the start: Sherlock's man. Biology could go hang.
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