A/n: This is the first thing I've ever written for sword art online although I first watched the series 3 years ago? Maybe more I don't have a clue?

But I rewatched it over Christmas and had this ides which sat in my drafts for three months until now where I'm stuck inside with terrible writer's block and the only thing I can seem to write is this hehe

This might be pretty bad and kinda disjointed because of me leaving it for months then coming back but oh well, I'm glad it's finally finished and I can cross it off my list of things to finish

Anyway, I hope someone finds some enjoyment in this hehe:)))

Kirito had never had the best home life. He had always felt he didn't fit in somehow, whether it was all in his imagination, he never quite worked out. At first, things had seemed to slot into place when he was around 9 years old. It had always been obvious he was different from the rest of his family and, upon enquiring about it, he had been told the truth. About his family and bout how he wasn't related to them in the same way he had originally thought.

Only things didn't change. He still felt cut off, isolated from the rest of society. At school, he barely had any friends and at home, he spent more and more of his time playing video games, finding it gradually becoming harder and harder to act normally around his 'family'.

The day he presented only helped to bring to light another reason why he was different.

He was a beta.

Out of the three possibilities, alpha, beta or omega, it was least common to present as a beta.

It was just his luck to do exactly that.

The actual day he presented was one he didn't like to remember in too much detail either.

Only, it turned out that none of this actually mattered as his life was turned upside down on the day of sword art online's release.

Suddenly everything he had previously been worried about, friends, family, his sub gender, none of it mattered, replaced with the worry that if he died here, he died completely.

It now didn't matter if he was excluded, different or alone. In fact, it was for the best.

Besides, his sub gender happened to provide him with an advantage for once in his life as at least he didn't have to suffer through heats or ruts.

Too bad it was simply used as another reason that he was a so-called 'beater'.

Not quite.

The only thing it made him was a beta which it seemed many people had forgotten even existed. As rare as they were in the old world, the actual world, they were even more so in sword art online.

Kirito was at the point of believing that he must be the only one here, having yet to find even a hint of someone else having the same sub gender only, he found it somewhat liberating. It was another reason for people to avoid him and leave him alone, many people finding it worrying how he never took a break from the front lines due to a heat or a rut.

There had been one exception, however.

From the first day they were stuck here, when Kirirto had met Klein, the redhead took it upon himself to check in on Kirito as often as he could. He didn't seem to care about sub genders or beaters or anything really but it was becoming increasingly hard to ignore the stifling sexual tension he felt anytime he was around the redhead and so, he had recently resorted to trying to avoid Klein regardless of how bad it made him feel.

They happened to run into each other after a recent boss fight, Kirito having not left quite fast enough and Klein doing his usual thing of trying to convince Kirito to join his guild regardless of how often he refused only this time, something was different.

Kirito couldn't pinpoint what exactly but there was something about Klein's demeanour which was off. He leaned closer to Kirito with every word he spoke and it was almost as if he was drunk, slurring words together. It was only when Kirito took a deep breath that realisation hit him.

Klein's scent was off...

He was going into a rut.

He had to get Klein home, and soon. Otherwise, there was no chance Kirito would be able to carry him.

"Klein, we need to go," Kirito spoke quietly seeing as they were surrounded by a rather large group of people.

"You're finally going to join us?" The redhead asked, a grin plastered on his face

"No, Klein," Kirito gritted his teeth, the scent of rut increasing by the second "You're going into a rut, you need to get home,"

"Hm?" Klein seemed confused for a moment before understanding washed over him "So I am, care to join me?"

Kirito froze at the words, the exact words he had hoped Klein wouldn't utter.

It was too late now.

"Klein...I.." How did he even respond to that? What did he want? A million and one questions raced through his head as he tried to sort through the jumbled mess that was his feelings.

On one hand, he wanted to agree, to spend the night forgetting his troubles however there was always a part of him that felt bad for indulging himself. They had been trapped in this death game for too long and he had promised to himself to work as hard as he could to get them out of there, was it really right for him to take time off working towards that?

Klein seemed to notice his inner turmoil, flicking him on the forehead lightly with a grin, his breathing heavy as he teased

"You're thinking too much about it,"

"I guess I am," The shorter male gave a weak smile "Let's go, I think I'll take you up on that offer too,"

The walk back to Klein's house was quiet, with nothing but subtle glances exchanged between the two until Klein pointed out a building.

"We're here,"

They entered the house quietly even though Klein lived alone and almost as soon as the door closed behind them, Klein was pressing Kirito against the door, hands resting on either side of his head to trap him in place as he slammed their lips together, not caring about their teeth hitting together.

"Fuck..Kirito I don't think you know how long I've waited for this," Klein breathed against the shorter males lips, grinding their hips together desperately.

"Oh, I know..." Kirito replied teasingly "I just wasn't sure about it," His voice was quieter as he added the last part but Klein picked up on it easily.

"I'll make sure you won't regret it,"

With that, he moved to hoist Kirito's legs over his hips, arms wrapping around his back as he began walking to the bedroom, practically throwing the dark-haired male onto the bed and grinning slightly as his small frame bounced.

"Strip," Klein ordered, puling up his own home menu to remove his clothes and watching as Kirito raised a shaky hand to do the same.

Once they were both completely bare, Klein simply let his eyes roam over Kirito's body appreciatively, enjoying the flush that rose up his face before moving to straddle the shorter male, gripping his wrists in one hand and pulling them up above his head to pin them to the bed.

The sight before him was breathtaking, pale skin stretched out, ready to be marked and abused by him.

Only by him.

Choking on thin air, Klein realised his rut was now fully kicking in, letting out an animalistic growl as desire washed over him.

"If I hurt you please, punch me, kick me, anything, okay?" Klein spoke quietly, his breath fanning over the side of Kirito's neck as he lowered himself to begin biting and sucking at the skin desperately.

With one hand still pinning Kirito's wrists down, he used the other to begin rummaging in the drawer on his bedside table, pulling out a small bottle with a victorious grin, allowing his teeth to nip at the dark-haired male's neck and trail down to his chest

"Keep your arms there," Klein growled before releasing his grip and sitting up further to grab the bottle of lube and coat his fingers with it.

Although his brain was clouded by his rut, he didn't want to hurt Kirito and also wasn't sure whether he had done anything like this before, deciding it would be best to be safe and to prepare the dark-haired male.

Kirito followed Klein's command, keeping his arms where they were and clutching the bedsheets tightly in anticipation and slight nervousness. Although he had never done anything with an actual person, he'd played around with different toys so he knew what to expect.

Despite this, he still found himself flinching slightly when Klein moved his legs over his shoulders, cold, lube covered fingers coming into contact with his entrance.

"Kirito..." Klein moaned out as he began pressing a finger inside, leaning down to suck and bite dark hickeys into Kirito's skin as he moved one finger inside the shorter male, slowly stretching him out and adding another finger.

"Fuck...Klein..." Kirito hissed out, the feeling of Klein fingering him quickly becoming too much.

"Kirito...If you keep moaning like that I'm not going to be able to hold back," Klein responded, his self-control wearing thin the longer he watched Kirito writhing beneath him.

"Then don't," With that, Klein practically ripped his fingers from Kirito's entrance, placing one last hard bite on his nipple before wiping his fingers on the bedsheets and reaching over to the drawer again to grab a condom and roll it on hastily

Even trying to take a steadying breath did nothing to calm the raging arousal he felt rushing through his veins and he finally felt the last of his self-control snaping, grabbing Kirito's shoulder to flip him over and lifting his hips. The position he was in made Klein practically growl in arousal, draping himself across Kirito's back as he slowly began pushing in, his self-control hanging on by a thread.

At this point, Klein was too far gone to register anything really besides the pleasure that coursed through his body, unable to recognise the small grunt of pain that Kirito let out as he pushed all the way in, starting a brutal pace right from the start.

Kirito felt a sharp pain rush through him as Klein finally fucked into him, wincing slightly as he realised he probably could have done with more preparation, however, that didn't matter as Klein began thrusting, the angle he was hitting making Kirito forget all about the pain.

"You're so tight...Jesus.." Klein moaned out biting down on Kirito's shoulder who simply groaned at the jolts of pleasure from Klein's thrusts.

"Klein..." Kirito panted desperately, feeling one of Klein's hands rech to grab his wrists again,the other resting on his hip as the redhead pulled him back against his chest, his thrusts never slowing as the dark-haired male writhed against him, desperately trying to push back against him.

The main problem Klein had found with spending his ruts with someone was that the increased hormones and desperation always make it end too quickly and it was much the same situation right now. He could feel his release approaching quickly, reaching down to stroke Kirito's hard cock whilst he bit and sucked at the junction where Kirito's neck and shoulder met. The place where an omega's scent glands would normally be. Klein couldn't get himself to think straight, even as he noticed that no matter how hard he sucked and prodded at the glands, Kirito's scent stayed the same. He wanted to be overwhelmed by the shorter males scent however it didn't seem possible despite how long he spent teasing the skin there.

His hips were jerking erratically now, desperate for his release as Kirito pushed back against him, seemingly enjoying himself as much as Klein was.

And then it happened.

Klein felt the rush of pleasure coursing through him as he reached his orgasm, pulling Kirito close to him as his knot began swelling inside the shorter male, his hand still stroking Kirito's dick for a few more minutes before the dark-haired male followed suit, releasing over the bedsheets before a loud cry escaped him.

"Argh, Klein!" He tried to pull away, pain clear in his voice as the redhead's knot continued growing bigger, stretching Kirito's entrance further than it was intended to and locking them together for the foreseeable future, however, it was already too late and Klein knew that Kirito would only hurt himself further by continuing trying to pull away.

"Fuck..."The word was barely a grunt as it escaped Kirito's lips, his entire body tensing in pain as Klein regained his senses enough to realise what was going on.

"You're...Not...An omega..." Klein followed suit in tensing slightly, willing himself not to move and risk hurting Kirito more "Kirito...I'm so sorry...I should've realised..."

"Ah...No Klein...You're in a rut, I shouldn't have agreed to it...Besides it...it doesn't hurt as much now..." The dark-haired male shifted slightly as if to prove his point, a shiver running all the way down his spine.

"Still...Are you sure you're alright?" Klein's voice was filled to the brim with guilt and regret and Kirito hated it, turning his head over his shoulder as far as he could to look at the redhead and give a small smile.

"I..I kind of like it..." He relished in the way Klein's eyes widened in shock "Don't get me wrong it hurt like a bitch to start but now..." he pushed back against Klein, shifting the knot inside him and feeling his breath catch in his throat.

"Fuck, Kirito...Don't say stuff like that...You're going to drive me crazy..."

"That's the plan," The dark-haired male grinned before adding with a slight wince "Can we maybe change position though, my neck's going a bit stiff..."

Klein nodded hurriedly, arms wrapping around Kirito and lifting him so that he could shuffle around enough so they were both laid on their sides, legs tangled together so that Klein's knot didn't pull against Kirito too much.

"I think with more preparation this would be amazing," Kirito sighed, shuffling back into Kleins touch.

"Believe me, now that I know you're a beta I'm going to spend at least an hour fingering you before I do anything," Klein grinned, placing another kiss on Kirito's neck to say sorry once more.

Kirito let out a quiet moan at the thought, unknowingly jerking his hips back against Klein who hissed at the sensation.

"We should get some sleep whilst we can before the next wave hits," Klein suggested, seeing the dark-haired male nonresponse

"Hmm,"

Klein grinned at the response, settling down with his arms wrapped tightly around Kirito, commenting quietly as Kirito began to drift to sleep.

"I guess my persistence finally wore you down,"

With that, he also let his eyes slip closed, enjoying having Kirito's warmth pressed against him after all this time trying to win him over.