Chapter Text
Chapter 00: Prolog ✨
Atsumu felt uncomfortable in his own skin. He was nearing his heat and everything felt wrong, every texture against his skin set it ablaze or itching. He felt like he was wearing a too-tight sweater that was choking him, which was impossible since he refused to wear anything but a loose t-shirt these past few days. It still wasn't enough.
A whine clawed its way from his throat. He hated this. If those stupid Alphas had managed to pup him the last time, he wouldn't have to go through this right now.
A pout formed on his face and he crawled back under the blanket. Said stupid Alphas and his lovely Beta mate were all currently at work, leaving him alone in their house.
His eyes shut close and he tried desperately to fall back asleep, chasing the thoughts of all the fun he was missing out on at practice away which only led to him thinking of his mates. Although his heartbeat quickened and he felt the echo of love from his bond it also cause his chest to hurt with the heartache of being alone.
He clung to the blankets and sheets covered in their scents. Closest to him lay Kita's pillow emitting the lingering aroma of vetiver and ginger. It was mild and sweet compared to the other two, not as strong since he was a Beta yet to Atsumu it smelled like heaven and he buried his nose deep into the fabric.
It was reassuring but lacking the warmth and comfort having his mate actually by his side usually brought. He sighed and pulled the blanket above his head. Maybe if he blocked out the sun he could just sleep through this.
An Omega would fall into heat every three months and pre-heat was the worst part of it in his humble opinion. That was ever since he had mates to spend his actual heat with. It made things much easier and shortened the time he had to take off from work. Which meant he would be back to playing volleyball very soon.
...
Not for too long though if their plan would work. If it would actually take this time.
Ever since last month and following long discussions and carefully mapped out plans they were trying for a baby. It hadn't been an easy decision. Atsumu would have to pause his career and the overall stigma surrounding the return of an Omega in the sports world after such an event weight heavy.
It only fueled his spite to prove them wrong though and after talking to his coach, partially to alleviate Sakusa's concerns rather than his own, he was certain. He knew that the team had his back and as long as he didn't slack off while still being responsible he could do this.
Additionally, he had three wonderful mates at his side that would support him no matter what... except for right now.
He whined again silently cursing all three of them for having jobs to tend to and stupid society for demanding money for living and keeping them from him. And overall human nature and everything he could think of up to the sun itself, for shining brightly and allowing for harvest so that Kita had no choice but to leave.
The hormones of pre-heat always left him an emotional mess to the point where he didn't want to know what pregnancy would end up doing to him. But everything for the baby.
Deep breaths.
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~ NSFW warning START ~
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After much trouble, he managed to fall asleep... but not for long. He was rudely awakened by a sudden wave of warmth surging through his body, causing a groan to slip past his lips.
He didn't even need to think twice to know, his heat had started. And none of his mates were with him... great. His body felt as though someone had set it ablaze and he was torn between feeling uncomfortable and needy as the slightest bit of fraction caused pleasure to ripple through his system.
Automatically his hands slid down. He felt his cock growing stiff and slick assembling between his folds. His breath hitched as he coated his fingers in the sticky substance and worked to take off the edge, jerking himself off with quick experienced motions.
It didn't take long until his resolve caved and he came over his hand, panting heavily and still far from satisfied but at least the fog invading his mind cleared a bit.
It cleared enough for him to reach for the phone on his nightstand and call Sakusa, who was closest. Their home wasn't far from the gym MSBY trained at.
The call was accepted almost immediately.
"I'm already on my way. Five minutes."
Atsumu smiled. Of course, he was. He could hear the strain in his voice and the smile turned into a smirk.
"Say, Omi, I hope no one noticed you getting all hot and bothered for your mate just now. How will I ever be able to look them in the eyes again?" Atsumu dramatically let himself fall back, listening to Sakusa grumble something rather inaudible though he dared to believe he heard the word 'punishment' and his grin grew wider.
In reality, he only found it fair if Sakusa embarrassed himself a little, for leaving him alone like this.
"Be careful though. Don't rush home. I'll be fine and still here when you arrive." his voice turned from teasing to serious but he couldn't help the whine accompanying his words. He wanted him home. Now. But it was more important that he didn't get into an accident on the way.
He heard Sakusa sigh but the ace promised nonetheless to be careful. He promised to be with him as soon as possible and hung up.
Atsumu looked at his phone with longing, his own disheveled-looking reflection looking back at him. His brows furrowed. He looked like a mess.
It wasn't unusual in his pre-heat but suddenly it bothered him. A lot.
Omi doesn't like messy things.
He forced himself up and a little wobbly made his way to the bathroom and climbed into the shower. The water felt uncomfortable on his overheated skin and he hurried through the process of washing himself off.
He was just in the process of drying his hair when he heard the front door open and forgot all about it. Naked he made his way to the hallway, where Sakusa was currently in the process of taking off his shoes and jacket.
The Alpha looked up at him as he heard his steps and his eyes widened a little at the sight, his pupils dilating. Still, he put everything away patiently before approaching him.
"How are you feeling, love?"
His touch was gentle as he cupped his cheeks and kissed his temple.
"Horny and like you're way too much of a tease."
Sakusa laughed at his blatant answer and suddenly his hands were at his waist pulling him closer and kissing him deeply.
"I'm the tease, huh? Weren't you the one calling out through our bond while I was still at practice, demanding I drop everything on the spot just to get here?"
He pressed himself closer to the spiker, burying his nose against his neck and breathing in deeply. The scent of patchouli filled the air with a hint of eucalyptus growing more intense by the second as aroused pheromones filled the room.
"Omiii~ No teasing. Please."
He grabbed his collar, pulling him into a heated kiss, and tried luring him to the nearby couch but Sakusa remained firm in his resolve. He kissed him back equally fiercely and passionately but wouldn't move one bit in the direction the Omega tried to guide him. A whine build up in his throat but was cut short when he was suddenly lifted into Sakusa's arms.
"We're not gonna mess up the couch, Miya"
The Omega rolled his eyes but snuggled closer to his chest nonetheless. It was warm, comfortable, and reassuring.
His Alpha gently lowered him onto the mattress, capturing his lips in a loving kiss again. He could feel his hands exploring his body, mapping out the skin and contours of his sides and hips, and leaving a trail of lingering desire in its wake.
Soft moans mixed into the kiss and he got to work on getting rid of Sakusa's shirt with ease.
"Safe words?"
"Green for everything 's 'kay, yellow for slow down, and red for stop. Yer's?"
"The same."
He deepened the kiss again and pulled Atsumu into his lap until he could feel his slick leaving stains on his pants, his cock leaking pre-come onto his lower stomach. Atsumu groaned as felt the bulge and not so gently coaxed Sakusa to lay back.
A cocky smirk spread on his face as took control, hovering over his Alpha in anticipation.
"What's yer color, Alpha?"
His voice had deepened and he could see the effect it had on Omi. Slight shivers ran through his system and his cheeks were flushed pink.
"Green."
He pulled him down but instead of kissing him started to attack his neck, sucking and licking over the soft skin and working masterfully around his scent gland and mate marks. Atsumu made quick work of the ace's pants, leaving both of them naked.
A noise of surprise escaped his throat when Sakusa slipped a finger into him without much warning and used the moment of inattentiveness from Atsumu to regain control. He placed him on his back again and gently worked on stretching him open.
A rush to pleasure rippled through his system as he felt Sakusa's fingers exploring his insides, the warm slick walls engulfing them tightly. The ace set a steady rhythm while kissing an invisible trail down Atsumu's chest, never averting his eyes from the setter's face. He was gorgeous.
His cheeks flushed and eyes glossy, variating between observing him closely and falling shut as the waves of arousal overtook him. He was panting, his chest rose and fell in unsteady intervals and Kiyoomi loved all the little noises he could pull from him. Quiet whimpers and desperate moans accompanied by breathy whispers of his name.
He let out a breathless groan of his own as he reached Atsumu's thighs. His fingers were still working him open while he set out to worship the beautiful soft skin and hardened muscles, twitching under his touch. Miya Atsumu was a piece of art.
He licked over the slightly golden-tanned skin, left marks on the still-empty canvas, and listened to the symphony it created.
"Omiii~ Please..."
It wasn't fair and he knew that. But he also knew that Atsumu could endure it, that all the teasing would be worth it in the end, and that if it ever got too much the Omega only had to say one word and he would stop immediately.
He grinned and looked up into those golden eyes that pulled him in and never made him want to leave.
"What do you want Tsumu? You have to tell me."
He straightened his posture and pulled back a bit, removing his fingers from Atsumu's entrance. It earned him a whine that slowly morphed into a frustrated groan as he glared at him.
"Touch me."
The dangerous glint of excitement grew even more prominent in the Alpha's eye and he nonchalantly noted:
"I am touching you."
Making a point by digging his nails gently into his thighs where his hands were resting.
Atsumu huffed breathlessly.
"You know what I mean."
For a second Sakusa considered pushing it further but then his gaze softened as he noticed the heavy scent of Atsumu's arousal being tainted with a slight note of distress. He leaned down and kissed their mark on Atsumu's neck as his hand drew conciliatory patterns on the marked-up skin, before gently guiding himself to Atsumu's hole.
"Yes, I know. I love you Atsumu."
Warmth engulfed him, a heat that despite being far from foreign to him always caught him off guard anew. A deep moan escaped his lips as he slowly filled the Omega. Atsumu's eyes closed and his mouth fell open in pleasure.
For a moment, he halted, settled into place, and allowed the overwhelming sensations to wash over him. He wouldn't last long. Not with Atsumu's sweet honey scent filling up the air, heightened and intensified by his heat. With every breath, he could taste it. The slight sweetness, the delicious aroma of their scents mixing, and Atsumu. So much of the strong Omega was present in the air, and it was all Sakusa could think about.
This was his mate. He loved the blonde setter with all his heart. His golden eyes like the setting sun, his comforting scent, and most of all his endless ambition mixed with subtle compassion. Every aspect of Miya Atsumu was shining in a warm bright light, like igniting embers.
Sakusa's world had never known warmth until he met him. Atsumu lit him up and before he knew it he got burnt by his fire. Soon Aran's gentle nature provided a calm to the storm. Kita was like an icy breeze. A Kitsune of the wind that could either fan the flames or suffocate them.
Just like Sakusa, he knew what it felt like to live in an eternal winter that started to melt when Aran and Atsumu brought them a forgiving spring.
He leaned down eyes trained on the marks at the Omega's neck right around and above his scent gland. A small whimper escaped the setter's throat as Sakusa licked over them gently. He shuddered as he felt the echo ripple through the mark on his own neck and gasped.
Desire burnt through him as Atsumu's fingers dug into the flesh on his back, marks he'd wear with pride. He set a fast pace finally giving in to the pleas of his Omega and reveling in the effect it had.
"Kiyo~, please I-... This time. I want pups."
His voice was merely a plea but every word left Sakusa shaking and burning with pleasure. He won't deny that as soon as the decision had been made he had been quite eager to give Atsumu exactly what he was asking for.
"I got you. I got you Tsumu."
He felt his relief approaching fast and before he knew it his teeth found their mark and he bite down hard, holding Atsumu in place with a mating hold while his knot popped and he filled him. The Omega beneath him shook with pleasure as his grip around the Alpha tightened and he screamed. Kiyoomi's name on the lips he slowly came down from his high and settled into Sakusa's arms.
His muscles were twitching slightly from the immense strain they had to endure but the air was filling with content pheromones and he let out a sigh of relief.
"Thanks, Alpha..."
Sakusa slowly loosened his grip, the taste of copper still on his tongue, and licked apologetically over the wound that was already closing rapidly.
"Color?"
"Green" Atsumy sighed exhaustedly.
"You?"
"Yes, Tsumu. I'm fine."
Sakusa chuckled slightly against his neck because to him the question was utterly silly. He hadn't been the one forced to submit and held in place by a mating hold. If he was honest the Alpha still felt weird doing that. He was scared of having the Omega entirely at his mercy, he never wanted to have this kind of power over someone.
It was the reason he originally avoided dating Omegas. Who could have known that after 4 years of dating, one and a half since they mated with Aran and Kita, Atsumu would show signs of secondary change? A process causing one's secondary gender to change, most commonly from an Alpha to an Omega or vice-versa.
Not everyone had this ability, it's said to mostly occur in pairings that otherwise wouldn't allow for biological children or in rare cases when someone is essentially born in the wrong body. Sometimes the process would happen naturally other times it was chemically induced by giving specific hormone injections.
People that can undergo multiple switches this way used to be called super-breeder but that term is long since outdated and seen as derogatory. Nowadays one such person would be referred to as secondary-intersex or secondary-fluid.
Atsumu showed no signs of such fluidity and was therefore a trans-omega.
An old term for this transition from Alpha to Omega used to be called bitching. It traced back to the practice of forcefully and most of the times violently forcing Alphas to submit to induce the change and for example extend an emperors' harm this way without the controversy of Alpha-Alpha relationships that were seen as useless. In other cases it was simply a display of cruel dominance by noblemen and the newly create Omegas were discarded afterward to die in the streets or if they were lucky, survive and bare the nobleman's bastard.
When they first discovered what was happening with Atsumu guilt possessed his consciousness. If he and Aran weren't Alphas, if they didn't choose to mate maybe Atsumu's life wouldn't have been turned upside down like this. When Atsumu heard that he threw a fit, how dare Sakusa doubt their bond or even worse regret their mating?!
In fact, despite being a little shocked at first Atsumu quickly found that he was quite content with the turn of events and turned down any treatment that could have prevented the process from completing. He accepted and loves his new body as though he'd never been any different.
Sometimes Sakusa wondered if that's how it was supposed to be from the start and that's why it happened so easily. It wasn't unheard of, just like some were born in the wrong body in terms of their primary sex, some felt wrong with their secondary one as well and desired to change it.
While Atsumu never expressed such desires he was happy now, maybe even more than before and Sakusa knew he didn't lie to them to make them feel better. He could feel it through their bond. Back then the just one-year-old mark was fairly new and he still had to learn to rely on and trust the constant flow of information trickling in through the mark at his neck.
.
.
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When Aran came home both Sakusa and Atsumu lay soundly asleep in the nest, snuggled up together, marked up and exhausted. The air was still heavy with pheromones and he was quick to open a window to let in some fresh air.
It didn't help the effect it had on him though. He looked down at the bulge in his pants filling out and sighed, his cheeks warming with a traitorous blush.
In a clumsy attempt to distract himself, he went to the kitchen and started lining up some water bottles and snacks, they would need them soon once Atsumu's heat was in full swing. Though it looked like they had already been up to a rough start.
He wasn't even halfway done when the sound of footsteps caught his attention. He didn't need to guess he knew that intense honey scent. Atsumu.
The Omega wobbled more than he actually walked and Aran couldn't tell if it was the heat or if Sakusa had been a bit rougher on him than expected. He was quick to rush to his Omegas side, his instincts to protect on edge the moment he sensed his mate's heat.
"Shouldn't you stay in the nest and rest? Surely your still tired from—"
He stopped as he saw the veil of want clouding his eyes. The moment Aran reached him Atsumu pressed himself to his side and buried his nose against Aran's scent gland, his nostrils filling with the tender sandalwood scent as he desperately licked over it for more.
"T-tsumu..."
"Please scent me Alpha."
Aran nodded. He picked Atsumu up in his arms and settled them both on the couch hugging the setter tightly while bringing his wrist up to cover him in a thin layer of his pheromones. Immediately Atsumu started to relax. The spiker started to gently massage his sore muscles and made sure to keep his touch gentle around the marked areas.
"How are you feeling?"
His deep voice was laced with compassion and concern. He kissed the soft spot under Atsumu's jaw, just below his ear, and listened to the content sigh escaping the Omega's lips.
"Tired... but..."
"Hm?"
Aran's head perked up and he searched the golden eyes for answers.
"I want you."
Aran could feel his pants tightening uncomfortably.
"Tsumu, are you sure you don't wanna rest some more first? Your heat will still last for a couple of days. It's okay to take it slow."
However, the setter had other plans as he pressed down on his lap, grinding himself against his still-clothed cock. Aran groaned.
"I don't want to 'take it slow', want yer pups, Alpha."
His voice was breathy, and a little hoarse. His body was burning up again and he needed his Alpha to take the edge off, he needed him to satisfy the deeply rooted heat roaming inside him.
"Okay, safewords?"
Atsumu groaned and let his head fall onto Aran's shoulder.
"Come on, Love. You know it's important."
"Green for okay, Yellow for slow down, and red fer stop. There. Happy?"
Aran laughed. He only understood half since it was muffled into his shirt but he understood enough.
"Very. Now, what would you like me to do?"
"Fuck me."
He laughed again, kissing the mark on Atsumu's neck, connecting them.
"I got that, but how?"
He seemed to think about it for a moment, his mind too foggy to come up with something elaborate. Before Aran understood what was actually going on Atsumu had untangled himself from the hug and let himself fall onto the couch next to him. He half laid, half propped himself up on his knees and underarms as he looked at Aran expectantly. He was presenting himself.
"Damn Tsumu, what happened to your usual pride?" he teased.
The blonde commented it with an annoyed groan.
"Are ya gonna help me or do I hafta wake Omi? Besides I trust you so..."
He blushed at the last part and Aran would have loved to tease him some more about it but settled for finally taking action before the Omega actually decided he was taking too long. Not to mention that his pants had long surpassed the point of 'uncomfortable'.
He disregarded them carelessly. His hands mapped out Atsumu's posture, feeling the hot skin littered with goosebumps as he caressed it softly.
"You're gorgeous, darling."
Atsumu whined softly, which turned into a moan as Aran's hand dipped between his legs. He felt the slick coating his fingers as he traced the wet folds up to the Omega's hard dick, squeezing it and pulling a desperate high-pitched sound from the setter.
"Aran... Not fair. Come on, don't ya wanna give me pups?"
Aran smiled at his impatience. Atsumu was known for being the neediest of them and a brat when it came to that. But the Alpha was used to it and he wouldn't want to have it any other way.
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~ NSFW warning END ~{
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Kita found them half an hour later, still knotted and half asleep on the couch. He was home the latest due to some complications at the farm.
All was fine now and his boyfriends obviously managed Atsumu's heat well so far, though he sighed as he saw them in the living room.
Sakusa would get mad once he heard about this. Kita walked into the kitchen, where Aran had stacked the snacks, and made quick work of completing what the Alpha had started. He checked their inventory, not just food and water but meds and heat pads as well. Next, he moved on to prioritizing and planning their laundry. They would need to keep track of washing the sheets and blankets before they ran out.
Next, he needed to prepare a bath—
A small whine tore him from his thoughts and he walked over to the couch quickly, following the noise. Atsumu frowned a little clearly uncomfortable. Kita kneeled down before him observing his face closely and searching their bond for any hint of what could have caused his distress.
"Atsumu?"
He gently shook him awake and brushed the few strands of hair sticking to his forehead from his face.
"Shin...?"
He loved hearing him say his name and even now a small smile tugged at his lips.
"Yes, I'm here. I got you. Why are you experiencing discomfort?"
His brows pinched together slightly in concern.
"No'thing... Just the heat. It's hot and... 'ncomfortable and I feel sticky and disgusting."
Kita leaned down to kiss his forehead before he got up.
"You could never be 'disgusting'
"Wake Aran, I prepare a bath for you two."
"M'kay"
Chances were high that he would have to come back and do it himself but he didn't mind, it wouldn't surprise him.
What did surprise him however was to find Sakusa practically passed out in their nest, cum, sweat, and slick still drying on his skin and the blankets in complete disarray. He should have guessed it, considering they didn't cross paths yet. Sakusa's influence through the bond was always relatively subtle and often overshadowed by the other two, so he didn't immediately notice that it was too subtle even for Sakusa. He was soundly asleep.
Kita prepared the bath and this time went to wake up Sakusa first. The sooner the ace would get a chance to clean himself the better. He walked to his side and gently rubbed over his arm.
It wasn't hard to gain his attention even in sleep. He slept fairly lightly... As though he never felt safe with anyone. A nervous habit he had long before they met and which Sakusa still struggled to unlearn. Kita was happy when it took longer than usual despite trying to fix everything at once on a tight schedule constructed in his head.
"Shinsuke...? what...?"
He blinked awake and groaned as his muscles protested the motion. His brows pinched together and disgust reflected in his eye as he noticed the drying layers of fluids on his skin.
A small chuckle resonated within Kita's chest and he stepped back a bit knowing very well that Sakusa didn't like to be touched when he felt uncomfortable like this.
"I prepared a bath, chances are that Tsumu will join you in a bit."
"Okay. Thank you."
He smiled despite his discomfort and even leaned forward to briefly kiss the Beta. Kita took it with pride and a small smile remained on his lips as he walked back through the living room, the dirty bedding in his arms.
His gaze fell on Atsumu and Aran on the couch finally separated and stretching their tired muscles.
"You should hurry. Kiyoomi is still in the shower and will take a bath afterward. You should join him Tsumu but don't let him catch you on the couch."
They flinched, looking around as though suddenly aware of what they did. Aran nervously scratched the back of his neck and stopped Atsumu who got up to help Kita.
"I'll do that, you rest. Shinsuke is right, join Kiyo we got this." he hadn't even finished when he sensed Kita's icy gaze on him.
"You should rest as well, Aran."
"I will but first let me help. I can't let you do this all alone."
He got up and despite Kita's warning gaze took the sheets from his arms. Behind them, Atsumu dragged himself up from the couch and toward the bathroom. Judging by his wobbly steps Aran should have carried him instead of the sheets. The Beta sighed.
"Fine, you'll do the laundry, I'll tidy up the couch before Kiyoomi notices anything."
His gaze wandered down Aran's bare chest and broad shoulders, his muscles were defined by years of training and Kita would be lying if he claimed his gaze didn't linger longer than necessary.
"And maybe put on some clothes. You'll get to be naked more than enough the next days."
The ace grinned and the hint of a mischievous glint appeared in his eyes.
"Just 'maybe'? Am I distracting you? Do you perhaps like my outfit this way?"
Every attempt at making Kita flustered was pointless and would always backfire. He knew that, yet he couldn't help but try.
"Yes, I'm very attracted to you, Aran. It was one of the reasons I agreed to mate with you. However, right now we need to prepare for Atsumu's heat. Distractions would be counterproductive so if you could please put on some clothes the chance that we'll get everything done in time will increase drastically."
He said it matter-of-factly. No shame or embarrassment accompanied his voice while the Alpha's cheeks warmed under his vigilant gaze. He couldn't help but laugh as his heart swelled with pride for his mate.
"I love you, Shinsuke."
He gave him a quick peck on his temple before running off to their laundry room to wash the sheets and find some clothes per Kita's request.