Title: John - The BAMF Omega
Rating: M
Pairing: John/Sherlock
Wordcount: ~2,300
Warnings: alpha/omega dynamics, d/s undertones, heat-associated dubcon (that is, both partners consent, but due to "heat" some may question ability to consent)
Disclaimer: I do not own Sherlock, and I do not make any money from this fanwork.
Summary: John may be an omega, but he refuses to bow down to overbearing alphas. When John goes into heat, Sherlock learns this...quite thoroughly.

****

"John! John! It was the sister's TA! Brilliant, absolutely brilliant!" Sherlock yells as he bursts into the sitting room at Baker Street. "John! Did you... hear..?"

"Good morning, Sherlock," John greets, raising an eyebrow at him as he takes a sip of tea.

Sherlock takes a deep breath, stumbling back just a bit as the scent in his nostrils makes him light-headed.

Omega.

Every muscle in his body tenses.

John is in heat.

Sherlock cannot help the growl that rumbles in his chest - he can't. Because John is just sitting there, calmly sipping his tea and reading the morning paper in nothing but his bath robe, smelling of pheromones and musk and arousal, and Sherlock can practically taste him on the air.

"Mine," Sherlock purrs, stalking forward. John is an omega - in heat, oh is he in heat. Sherlock can feel the blood pumping through his veins - feel his penis stiffening, filling with blood, his knot getting ready to tie him to his omega.

To John.

Oh, this solves everything. He will mate John, and John will be his - his omega, and he will have to stop seeing all those silly betas. Sherlock will make him, he will, because John will be his. And oh, now John will have to listen, and stop being so stubborn all the time, because Sherlock is an alpha.

Sherlock is John's alpha, so John will have to listen. Oh, it's brilliant.

Sherlock takes another deep breath, shuddering in pleasure. He reaches for John, sitting there so prettily, and look - he's still damp from his shower, he is, but Sherlock can smell how wet he is already.

Sherlock blinks. He's on the floor. Why is he on the floor? His cheek is rubbing against the rug, and there is a warm weight on his back, and firm hands twisting his arms behind him in such a way that he would dislocate his shoulder if he tried to escape. His penis - oh, his penis is so hard. It hurts, straining against the zipper of his trousers and pressed down firmly against the hard floor.

"Are you yourself again, Sherlock?" a voice asks him.

Well, of course he is himself. Who else would he be? How stupid. Sherlock just growls in response, trying to twist away - oh, but bad idea, he's forgotten about the hold.

How has he forgotten?

He takes a deep breath, and - oh, it's John on top of him. Why is John on top of him? John is supposed to be below him. He wouldn't mind so much, really, if their positions were reversed.

"Sherlock, stop growling and get your wits together, please. I really don't want to have to knock you unconscious, but I will if I need to," John tells him firmly.

Why, he doesn't sound like an omega in heat. According to the telly, omegas in heat are all begging eyes and pleading words and compliant bodies, opening their legs to entice alphas with their slick, wet holes. John just sounds like... John.

"My wits are always together," Sherlock growls back. "And as soon as I get up, I'm going to show you your place."

"My place?" John replies, sounding incredulous. "Yes, because that is going to make me let you up. Maybe I should show you your place, hmm?"

John punctuates that statement by grinding his erection against the small of Sherlock's back.

"Would you like that, Sherlock? If you're good enough to make me come, maybe I'll even let you taste me, after," John leans down to murmur in his ear.

"John, John. Please," Sherlock whimpers, shuddering. How is he supposed to function? With John smelling and sounding and feeling like that, all warm and hard on top of him. "Oh, John."

"I'm going to flip you over. Don't fight," John tells him. He turns Sherlock on his back, pulling his jacket up to get all caught around his elbows, straddling his stomach and pinning him with his arms still behind his back. Sherlock is still too dazed by the smell of him to do anything but stare.

"John," he whispers, bucking his hips. John smiles down at him slyly. He shifts down so he is straddling Sherlock's hips, grinding down into his erection.

"I may be an omega, but I'm still in charge of my body. I may be in heat, but that doesn't mean I need anything more than my own hand and maybe a dildo. If anything goes inside me, it will only because I allow it to go inside me. If anyone touches me, it will only be because I allow them to touch me. I don't lose my mind when I get horny. That would be you, wouldn't it, Sherlock? You may be an alpha, but you're so out of your mind just from the scent of me that I could do anything to you now, couldn't I?" John says, punctuating each sentence with a roll of his hips.

And he's right. He's so right. Sherlock is out of his mind right now. And John could do anything - anything at all. Anything he wants. As long as he doesn't go away.

"John, John please," Sherlock begs, struggling against the jacket binding his arms. John just smirks down at him, moving back even further so he can reach down and unzip Sherlock's trousers. He slides them down just a bit - just enough so he can pull out Sherlock's penis.

Sherlock blinks down at it. It is very erect. Standing straight up. Almost like a soldier, at attention. Just for John.

"Mmm...look how hard you are, just for me," John whispers, pulling his bath robe up so it bunches around his hips. He moves forward again, rubbing their erections together.

"Oh," Sherlock moans, throwing his head back in pleasure and giving up the struggle. "Oh, please."

"What would you do, to convince me to let this inside of me?" John asks him, reaching one warm, perfect hand down to stroke him gently. It's not enough. It's not enough.

"Anything," Sherlock gasps. "Anything. What do you want? I... I'll bin the experiments. I'll take you to Angelo's as many times as you want. I'll buy the milk, I promise."

"And beans?" his beautiful, torturous omega asks, his thumb rubbing gently at the head of Sherlock's penis.

"Anything. Anything you want," he agrees.

The hand disappears.

"What?" Sherlock cries, but before he can cry for it to come back - it does.

And it - it's wet. Slick.

With John. Oh, Sherlock can smell it. On his penis. Oh, he wants to rub it all over. He wants to feel it everywhere, smell it everywhere. So everyone will know. And then maybe he can come, and rub himself all over John. Maybe John will let him, if Sherlock is very good. Sherlock... Sherlock should ask. Very nicely. Sherlock should...

"I'm going to fuck you now," John informs him matter-of-factly. "Is that alright with you?"

John... is going to fuck him? But Sherlock... Sherlock is the alpha. Sherlock should fuck John. But John... John is in charge. And if Sherlock says 'no', John might leave. What if he finds another alpha that will be willing to let John fuck him? He can't let another alpha steal John away.

And maybe... maybe if Sherlock is very good, John will let Sherlock fuck him later. Or at least touch him there, where he's all warm and wet and... John said he would let Sherlock taste, didn't he? If Sherlock was good? Sherlock can be very good, indeed, if it means John will let him taste.

Oh, just the thought of pressing John down, pulling those pert cheeks open - smelling him right there, so close to the source. Leaning forward, tracing his tongue around the rim, watching that pretty little hole wink at him - opening and closing, maybe some wetness trickling out for Sherlock to taste.

"Yes," he moans. "Fuck me, John. Oh, fuck me. Please. Please. I'll be good."

John smiles down at him brightly. He reaches down to stroke Sherlock's cheek. Oh, his hand smells like... Sherlock turns his hand to capture those fingers in his mouth, sucking gently. The taste... Sherlock can't help but shudder in pleasure. Oh, on John's fingers it is magnificent. From the source...

"You agreed to be good, so I'm going to let you up. I want you to take your clothes off and lie back down, afterwards. Just like this, on your back - with your arms crossed underneath you. I like this position, but it would be much better with you naked," John tells him - and then he gets up.

Sherlock shudders at the loss of him, but gets his bearings quickly. The sooner he listens, the sooner John will touch him again. He stands up, pulling his clothes off quickly, letting them fall where they will. Then he lies back down, just as John told him.

John smiles again, pleased. He unbelts his robe and shrugs his shoulders, letting it fall down to pool around his feet. Sherlock can see him, now. He's wonderful, all compact muscles and interesting scars and beautiful, sweet-smelling skin.

Sherlock spreads his legs - and John smiles, bending Sherlock's legs at the knees and pushing them together. Then he straddles his hips, reaches behind him to hold Sherlock's erect penis straight up, and...

Sinks down on him.

Sherlock moans like he is dying, as John's warm, slick passage parts around him. He's so tight and wet and... oh. Oh!

"I thought... I thought..." Sherlock murmurs, unsure what he thought. There is something... there... but...

John.

There is nothing but John.

"You thought I was going to fuck you," John agrees, panting. His pupils are blown wide with arousal, and his cheeks are flushed in pleasure. Pleasure Sherlock is giving him. Oh, Sherlock wants to thrust - he wants to flip them over, and hold John down, and...

But Sherlock promised to be good. And John can still leave, if he wants. Sherlock hasn't knotted him yet, he could just stand right up and walk away.

John rises up, letting Sherlock slip half-way out of him - and then he drops again, taking Sherlock in to the root. He grinds down, rolling his hips before pulling up again.

"I am fucking you," John tells him. "You might be inside me, but that's only because I enjoy this position. Because I get pleasure from your big, hard cock inside my hole. You would have let me turn you over and fuck your arse from behind if I wanted. Yes?"

"Yes. Yes. Oh, yes," Sherlock agrees, because of course he would have. It's John. John. John.

"Well, there you go. That's why I'm fucking you, rather than using my vibrator upstairs," John tells him.

Oh.

It is the last coherent thing either of them say for a while.

*****

"Oh," Sherlock moans, as John shudders in pleasure and clamps down on him viciously. His knot... his knot is expanding, inside of John. He can feel John clenching down on him, milking him, coming around him. Warm splashes on his chest. Oh, oh...

"Sherlock," John grunts, tightening his grip on Sherlock's hands where he is using them for balance. "Flip us."

Sherlock blinks up at him, confused. John just growls and rolls them, moving so John is on his back and Sherlock on top of him - all without Sherlock ever pulling out.

"Finish like this," John murmurs, bucking his hips up. "I shouldn't have to do all the work."

Sherlock complies, thrusting hard, but shallowly. He can't pull out very far - not with his knot blocking the way. John is writhing below him, obviously oversensitive after his own orgasm. And then - then he reaches forward to cup Sherlock's nape, and pulls him down for a hard, passionate kiss.

It is their first.

It is also all it takes for Sherlock to finish.

"Oh, John," he murmurs, as they wait for his knot to go down. He can't help himself - he has to keep kissing John. His lips, his cheeks, his jaw, his neck. Oh, John is so kissable. He knew before, of course. But now he knows.

"Well, that was my best heat in quite a while," John whispers, returning Sherlock's kisses when they fall on his lips.

"Quite a while?" Sherlock growls, not wanting to think about John letting other alphas touch him like this.

"Oh, don't go getting all possessive now, Sherlock," John admonishes him gently. "I've never let an alpha knot me before. I've always spent my heats by myself, or with the aid of a beta."

A beta?

Sherlock growls at the idea, letting his weight fall mostly on top of John - shielding him from the outside world. No one else can have him. Not another alpha, and certainly not a beta.

"Well, I suppose I can't keep you from being overbearing all the time," John sighs, gently caressing a hand down Sherlock's spine. "As long as you confine it mostly to post-sex when I'm too fucked-out to care, we should be fine."

"You're going to let me do this again?" Sherlock asks, half-incredulous and half-hopeful.

John smiles up at him fondly, running gently fingers through his hair.

"Of course. I said if you were good I would let you taste me, didn't I? As soon as your knot goes down, we're going to go up to my room and spend the rest of the day in bed. You were very good, after all - but I think we can do even better," John tells him, clenching down firmly around Sherlock's still-inflated knot.

The minx.

Sherlock wouldn't want him any other way.

In fact, he feels sorry for all those other poor alphas - those alphas that have no omegas at all, or omegas that just let their alphas walk all over them.

How dull.