A/N: And then I wrote a random one-shot Omegaverse fic because why the fuck not?

Warning: Omegaverse

Sherlock was not in love with John Watson. They were friends, the very best of friends and nothing more. Just because John smelled ridiculously good was no reason to believe it was otherwise. Sherlock wasn't jealous when other people realized it either. The way some of the other Alphas at school looked at John, knowing what he was. Sherlock wasn't jealous of the way other Alphas looked at John or even some Betas.

He wasn't jealous when John stated dating one of the Beta girls at school, Sarah. The only reason Sherlock tagged along to their dates was because John was vulnerable. Sherlock had to protect his friend who happened to smell amazing. It wasn't love, Sherlock didn't do love.

And if Sherlock had memorized John's scent, had it so far embedded in his nostrils that he usually used it as a masturbatory tool, well that was no ones business but his own. It was just biology, his Alpha genes had ingrained in him the need to be with an Omega. It wasn't about John. It was just that Omegas were scarce and Sherlock had been in contact with very few of them and never long enough to know their scents as well as he knew John's.

"Sherlock, you can't come over tonight." John told him over the phone.

"What, why not?" Sherlock demanded to know. He had spent the last three years sneaking into John's room at night. He hated being home in his big empty house where his parents ignored him. He preferred John's house where there was always noises to catalogue and deduce. Either Mrs. Watson cleaning or Harry yelling or Mr. Watson working on his car in the garage. John's house was full of life while Sherlock's was full of silence. Sometimes he liked being left alone with his thoughts but mostly he just found it boring at his house.

"I, um…you just can't."

"Has your father gone down to the pub again?" Sherlock asked. It was a Tuesday night, quite unusual for Mr. Watson but then alcoholics were often unpredictable.

"No." John replied curtly. He never liked Sherlock mentioning his father's alcohol abuse.

"Then what?"

"My family is going out of town."

"Oh, where are you going?" Sherlock asked, a sudden uneasiness in the pit of his stomach. He knew it was stupid; John would be back. He wouldn't be forced to brave high school alone like he had before John had moved there. John would be back.

"I'm not going with them."

"What? Why would they leave you home?"

John sighed heavily into the phone. "It's my heat Sherlock. I'm going into heat. My family is leaving to give me some privacy while it happens. My mom is going to come check on me every once in a while."

John's mom, Omega as well, safe, while Harry and Mr. Watson were both Alphas.

"How long will you be in heat?" Sherlock asked, wondering how long this forced separation would be in place.

"I'm not sure. It could be anywhere from three days to an entire week."

"Oh." Sherlock wasn't sure what to say to that but the hole in his stomach twisted uncomfortably. An entire week without John. They hadn't spent a week apart since they'd become friends. It meant being forced home with the vast nothingness and ever present boredom. He had enough ideas for experiments that he could occupy two of the days but what if John went the entire week? What would he do then?

Sherlock was fairly certain he was going out of his mind. He kept thinking about John being in heat and that caused him to be not only curious but almost perpetually hard. He'd wanked more in the last two days then he had in the past two months, thinking about John in heat. His scent would be stronger but how much stronger? What would he smell like now? How was he coping with his first heat?

Sherlock's mind was racing with thoughts of it. He could think of little else and it caused him to spend most of his time locked in his room, masturbating. Was this what it was like for John? Sherlock was undoubtedly curious. He knew the basics of what would happen to an Omega during heat but what would it be like for John?

Half out of his mind, Sherlock dressed quickly and ran the four blocks over to John's house. It had been two days; what if John had found someone to help him through his heat? John wasn't currently with anyone but he could entice anyone with his smell. What if someone was fucking John right that moment? What if someone were fucking his best friend? His John.

Bad idea, not good, bad idea, not good, he kept telling himself but the half crazed Alpha part of himself was not listening to his logical mind. Instead he scaled the side of John's house, climbing up the drainpipe as he had a million times. He was halfway up when he could smell it. John, undeniably John and so good. His mouth watered and his cock thickened in his trousers.

When he got closer, he could hear him. John was groaning and it sounded like he was in agony. Someone's hurting him! Sherlock started to panic and hurried up the pipe quicker. He pushed the window open and climbed in.

"Sherlock!" John looked shocked to see him. "What are you doing here?"

"I had to see you." Sherlock replied, stepping closer to the bed.

"No, stop. Sherlock you can't be here, I'm in heat!" John yelled, his face half buried in his pillow as he pushed back against his own fingers inserted inside himself.

"I know. I was curious."

"You have to leave Sherlock. Oh God."

"John, you sound like you're in pain. What do you need?" Sherlock felt a surge of protectiveness overcoming his arousal.

"I need a giant, thick cock up my arse!" John shouted in frustration. "I've needed it for the past two bloody days!"

"Didn't you get anything for your heat?" Sherlock asked, stepping closer and sitting down on the bed. He gently brushed his hand over John's sweaty forehead.

John whimpered and writhed, fucking himself on his fingers. "Harry offered to get me a dildo. I was too embarrassed to say yes. I thought I could handle it on my own."

"Clearly." Sherlock looked at where John's digits were doing an insufficient job of satiating him.

"I didn't know. I didn't know." John muffled against his pillow. "I didn't know it would feel like this. It's like my whole body is on fire."

"John, I want to help. Tell me what you need."

John bit his bottom lip, contemplating it. "Your fingers. Can I have your fingers? They're longer than mine. They might help."

"Oh." Sherlock was slightly surprised by John's request. He had been considering going out and buying John a sufficient sex toy. Sherlock wasn't easily embarrassed by that kind of thing. He hadn't expected John to want him.

"Please Sherlock." John begged helplessly. "Just your fingers. I think it might be enough. I just need to come."

Sherlock looked at his sweaty, needy, mess of a friend. He could give John this, help him, like John had helped him so many times over the years of their friendship. Good, loyal, sweet John with his dazzling smiles and his soft blond hair. John with his amazing Omega scent that drove Sherlock to distraction. He could do this for John.

Sherlock nodded and stood up to remove his coat. John instantly reached for him, placing his hand on Sherlock's leg. ""Please Sherlock. Hurry."

"I'm going." Sherlock rolled up his sleeves and got on the bed behind John. He smoothed his hand over John's bottom, causing John to moan against his pillow. He helped John ease his fingers out and was overwhelmed by John's scent. It was even stronger than he'd imagined. For a moment Sherlock wanted nothing more than to press his face between John's cheeks to taste and smell him. He shook his head to clear it and remembered he was supposed to stay on task.

John was rutting against nothing, his own hand gone and Sherlock's still absent. Sherlock steeled himself and teased his finger up and down John's crack. John groaned in frustration and began begging again. The sounds went right to Sherlock's cock and he looked down to see he had a damp spot on his trousers from his cock leaking heavily.

As he pushed a single finger inside, he wasn't prepared for how wet and warm it would be. John pressed back against him instantly and began impaling himself on that single finger.

"More. Sherlock please. I need more."

Sherlock pushed a second finger in and then at John insistence, another. He slipped his fingers in and out as John pressed back to meet them. Sherlock watched with fascination as his fingers were swallowed up by his friend. In fact he was so distracted by it he didn't even notice he was practically humping John's leg.

John whimpered again. "It's still not enough. God the way you smell."

"You too." Sherlock said, forcing his crotch away from John. "Tell me what you need."

"You." John replied instantly. "Fuck, Sherlock. I need you."

"Do you need someone or do you need me?" Sherlock pulled his hand away, slipping his fingers out of John, who made a disgruntled noise.

"You." He answered, flipping onto his back so they were face to face. It was only then that Sherlock saw John's cock, angry and red looking against John's stomach.

"What about all those Betas you date?" Sherlock eyed him suspiciously.

"You were jealous?" John asked, looking slightly bewildered.

He meant to lie, to deny it wholeheartedly but instead he found himself saying "Yes."

"Come here." John grabbed Sherlock by the front of his shirt and yanked him down on top of him. Their lips clashed together for a moment until John eased them into softer but heated kisses. It was Sherlock's turn to whimper, having never kissed anyone except family in his life. John knew exactly what he was doing with his lips and tongue, leaving Sherlock to mimic and follow as John snogged him thoroughly.

"You." John broke away and nuzzled him face against Sherlock's neck. "Just you, only you. I didn't think you were interested in this sort of thing."

"I wasn't. I can't help myself with you." Sherlock confessed, running his hands over John's body that was pressed so wonderfully against him.

"I'm on the pill." John informed him, finding his mouth again. Sherlock found he quite liked kissing John and couldn't believe he hadn't been doing it before today. "I wont get pregnant if you fuck me."

"Why?"

"Because the pill stops me –"

"No, I know what the pill does John. Why are you on it?" Sherlock asked angrily.

"It was just a precaution." John chased Sherlock's mouth, trying to kiss him again but Sherlock turned away.

"Were you expecting someone else?"

"No! I wanted you, I was hoping you'd come, that if I told you I was in heat, your curiosity would get the better of you. I know you like the way I smell. Whenever you sleep over you cuddle me in your sleep, rubbing your nose against the nape of my neck. God Sherlock, you're the reason I'm in heat now. The doctor told me I wouldn't go into heat until I turned sixteen but being around you so much caused me to go off early. My body's been craving you so much it forced me into a heat. And since you're the bloody cause of all this, the least you could do is fuck me!"

"Yes." Sherlock nodded and hurried started undoing his trousers. "Yes John, yes."

"It's you Sherlock, only you. You're the only person I'd ever let inside me. I need you. Please."

Impatient and needy, Sherlock only opened his trousers enough to push his pants down and release his cock. John turned back onto his hands and knees, presenting himself to Sherlock. Sherlock groaned in response, his cock aching.

"Do I need to use anything?" he asked, his voice somewhat hoarse.

"No, God, I'm so wet. Just fuck me."

Sherlock didn't need to be told again. He held the base of his cock in his hand and guided himself until he was pressed up against John's hole. Then his Alpha instincts took over and he shoved in with one quick slide. John's head snapped back and he moaned obscenely. Sherlock's body was on autopilot, lost in sensations and John. He fucked him roughly, needing release. John didn't seem to mind, begging him to go harder, faster, deeper. Sherlock complied, snapping his hips as he thrust into John over and over.

John grabbed the headboard to steady himself. "Sher – Sherlock." He moaned, taking one hand away to wrap it around his own cock. Sherlock was only slightly aware that he was babbling nonsense. To stop himself, he lowered his lips to John's spine and started mouthing his way up. He could feel his knot inflating and knew he was so close to coming. He felt John's body tense and shake as it was wracked with his orgasm.

Sherlock gripped John's hips tighter and thrust relentlessly as he lavished kisses to John's neck. His knot finally finished inflating, connecting them. Mine, he's mine, no one else can have him. But he might change his mind. He could decide he wants someone else. I can't let that happen, I can't. Mine, my John, mine. He was so overcome that he bit down on John's neck hard, breaking the skin. John cried out and reached back, fisting his hand into Sherlock's hair. Sherlock thought he was going to yank him away but instead he held him there. Sherlock went over the bite mark with his tongue, trying to sooth it.

They eased onto their sides, lying together as orgasm after orgasm shot through their bodies. When John's body was finished milking Sherlock's for all he was worth, the knot deflated and they were able to pull apart. Sherlock took the opportunity to undress fully and lied spooning John.

"When we go back to school, you'll smell like me." Sherlock pressed kisses to John's shoulder blades. "Everyone will know I claimed you."

"And if the smell doesn't tell them, this certainly will." John pointed to the bite on his neck.

"Sorry." Sherlock mumbled against John's hair. "I didn't mean to bite you."

"I didn't mind. In fact I liked it a lot. It made me feel…complete, in a way."

"Me too."

"I'm glad you showed up."

"I'm just sorry it took me two days."

"It's all right. Knew you'd get there eventually. For a genius you can be quite slow on the uptake."

"How is it possible that you saw this and I didn't?"

"Because you're an idiot."

Sherlock smiled against John's skin, not having it in him to argue.

"Ready to go again?"

"Ready when you are."

When they did eventually return to school, after John's heat had finished and they felt rested enough, John did smell like Sherlock. Or more accurately he smelled like a combination of the two of them. There were snide comments of course but neither John nor Sherlock paid them any attention. They had each other, so what difference did it make?

They had been sat down by both John and Sherlock's parents and explained that Sherlock biting John meant they were bonded. The Holmes family called for the bond to be broken, stating that they were too young to pick whom they were going to spend the rest of their lives with. Sherlock and John wouldn't hear of it. They belonged to each other, he was John's and John was his.

And it was going to stay that way for a very long time.