Posted originally on the Archive_of_Our_Own at https://archiveofourown.org/ works/7400296. Rating: Explicit Archive Warning: Underage Category: M/M Fandom: Haikyuu!! Relationship: Iwaizumi_Hajime/Oikawa_Tooru Character: Iwaizumi_Hajime, Oikawa_Tooru Additional Tags: Alpha/Omega, Mating_Cycles/In_Heat, Mating_Rituals, Mating_Bond, Mating Bites, Dirty_Talk, just_a_bit, Porn, Rutting Series: Part 4 of Mating_Night Stats: Published: 2016-07-05 Words: 1445 ****** Oikawa and Iwaizumi ****** by Bittodeath Summary There is an old tradition in the lost villages of Haikyuu, to make sure there are no unmated young people: once every three years, at night, all the youth between sixteen and eighteen are gathered at the entry of the village, Omegas and Alphas alike. They presented as either Alpha or Omega and, under the watch of the leaders of the village, Omegas are sent into the forest, to run and hide themselves. A moment later, Alphas are sent after them. The first Omega an Alpha manages to grab is destined to become his mate, and they have to mark each other during the night and come back to the village once mated. Notes Finally I finished this. Took me long enough. See the end of the work for more notes There is an old tradition in the lost villages of Haikyuu, to make sure there are no unmated young people: once every three years, at night, all the youth between sixteen and eighteen are gathered at the entry of the village, Omegas and Alphas alike. They presented as either Alpha or Omega and, under the watch of the leaders of the village, Omegas are sent into the forest, to run and hide themselves. A moment later, Alphas are sent after them. The first Omega an Alpha manages to grab is destined to become his mate, and they have to mark each other during the night and come back to the village once mated. This technique is not perfect, but everyone is mated and since their other senses are hindered, most Alphas rely on their sense of smell and end up choosing the “best smelling” partner, who is biologically the most compatible. Thus, blood lines are strong – and no one can complain that they were chosen or rejected. “Mating Nights” are joyous occasions, often followed by a consequent number of births.   Karasuno Village is a particularly remoted village, with only two women but luckily just an even number of young Alphas and Omegas. And the “mating night” as finally arrived, under the supervision of their leaders, Ukai and Takeda – or, as they are called now that they are mated, Keishin and Ittetsu. They have gathered all their young ones, eager, bored, excited or frightened. “It is night. You may go.”   Oikawa was probably the only Alpha who wasn’t nervous. After all, he had known who he would mate with for two years already. He couldn’t help but smile fondly. Two years ago they had made a promise, but somehow they had known they were meant for each other for much longer. Presenting as Alpha and Omega had only enforced their idea. Surprisingly enough, he was the Alpha. Surprisingly, until they adjusted to each other. Nature was not random. He bit his lips, impatient to go – and maybe the fact that his rut was drawing near had an impact on this. Usually, the Mating Night was scheduled for a night when no Omega would be in heat, and no Alpha in rut. But for them, of course, it couldn’t work that way. They had been together for long enough that their cycles had adapted to each other – it was rare, and proof of a deep bond between mates – and gave them a pleasure more intense than if they were to go through them alone. Usually, Omegas’ heats were at the same time when they lived with each other, just as in Karasuno Village. And it had been true for every Omega present on that night – except one. No one understood why, except the two of them. “C’mon”, he breathed, impatient. On his right, Daichi looked at him and smiled feebly: despite all his “Alpha acting”, he was as nervous as the others. Finally, Keishin gave the signal and they all sprung forward. Haphazardly, for all but one. Oikawa immediately ran to the “naked tree” – it had been struck by lightning a year ago and had lost its bark. He swiftly climbed up the tree, the enticing sent feeling his nose and making him dizzy, only hurling his rut. His hand met warm, very warm flesh – too warm to be someone else – and he smiled. “Got you, Iwa-chan”, he whispered in a sing-song voice. “About damn time, I was starting to think I wouldn’t be able to come down. My legs are trembling and I’m basically dripping wet”, the Omega gruff voice answered. Oikawa’s breath was stuck in his throat at those words. He slid his hand higher, along firm and robust arms, and accidentally brushed Iwaizumi’s scent gland, making him moan loudly. “Fuck you, Shittykawa”, he growled. “Sorry Iwa-chan”, the Alpha whispered, his arms and legs trembling from his uncomfortable position. “Do you need my help to come down?” “No, I should be alright”, Iwaizumi replied, and soon after they were both back on the ground. Oikawa grabbed his hand and pulled him toward him. Iwaizumi was incredibly hot, his skin slicked with perspiration as he slowly entered his heat. The sweet, heady scent was turning Oikawa mad. “We’d better hurry”, he said, dragging Iwaizumi to the nearest nest. They were probably the first to be ready to mate on that night, and all the nests should be empty. They were like cocoons made of branches, filled with leaves, feathers and wool, with a tiny entrance, a blanket and a small wooden cage full of ladybugs to illuminate the night. It did not take them long to climb in, nor to shed their clothes as the air around them warmed up and captured their scent. Iwaizumi chuckled when Oikawa kissed his lips gently, still able to control his speed and movements. “What is it?” the Alpha asked, creeping closer. “I’m thinking that it is their first time. All of them.” “They don’t know what they missed.” “But it must be awkward”, the Omega added, “like, they discover they are to be mated, they fuck for the first time and they mate? All in one night?” “Aren’t you glad I took your virginity so masterfully”, Oikawa bragged, a smug smile on his face. “You had never been so awkward, Crappykawa”, Iwaizumi answered, drawing near and settling himself in Oikawa’s lap. “That was the lamest fuck we ever had.” “We’re supposed to mate tonight, you know, but if you want to go with just a quick awkward fuck we can also do that”, Oikawa lied – he had things in mind for his Omega, and they were both too worked up by their cycles to be satisfied with just one quick round. “You’d resist me?” Iwaizumi asked, and he was dripping in Oikawa’s lap, warm and enticing with a scent that sent the Alpha reeling. “Like you could resist me”, Oikawa retorted, pushing two fingers in him and gasping at the heat. Iwaizumi stilled, his breath shortening and slowly turning into moans as his heat fully kicked in. He was usually lewd, that was something Oikawa had learnt at his expense, but when he was in heat… God, there was nothing to do when he was in heat. He was even lewder than usual and unabashed, using his deep voice and dirty talking to coax Oikawa into indulging him, and it always worked. Not that Oikawa resisted much anyway. “Tooru”, he murmured, his voice filled with promises, “please take me, mark me, bond me, knot me, please just do something.” He was fidgeting in the Alpha’s lap, rutting against his arousal, and it was turning the both of them mad. Oikawa forcefully grabbed him and threw him into the mattress after taking his fingers out, and lined up with him. “You ready?” he asked, though he knew he was. Iwaizumi nodded, muscles tensing as he tried to contain his nature and failed. The Alpha slowly pushed in, his pupils flaring when he bottomed out and he screamed, his rut taking over his mind. His hands grabbed Iwaizumi’s hips firmly and he started to thrust at a maddened pace that satisfied the both of them, though it was too much, clearly too much – but Iwaizumi was moaning about how good he felt, speared open with Oikawa drilling into him, and Oikawa couldn’t talk anymore, his jaw hanging low as he violently rocked them. Climax hit them quickly and suddenly, and finally they unleashed their instincts, leaning towards each other and biting their neck, leaving a red, angry mark – a bond. Maybe they hadn’t thought it over when they decided having their heat and rut during the Mating Night wasn’t a problem, or maybe they simply didn’t know it, but the pleasure of bonding triggered a second orgasm that ripped through them, leaving them boneless, shuddering and hazy. Finally, Iwaizumi hummed – his heat was coming down for a moment, to let him rest a bit before another round – and purred: “I love having your knot in me, you know.” “Yeah?” Oikawa replied, unable to move. “Yeah. Feels good. Like we’re connected. Two parts of a same being.” “You’re being sappy, Iwa-chan”, the Alpha muttered with a smile – of course he loved knotting his mate. “Am not.” “Are so.” “Am not.” Oikawa didn’t reply, his eyes were closed and he had fallen asleep on Iwaizumi. It didn’t take long for the Omega to join him into a blissful sleep. The morning sunlight found them slowly rocking and moaning together, once again taken over by their mating cycle. The only difference was the red biting mark on their necks – a bond, gift from Nature. End Notes I hope you liked it, as usual don't hesitate to comment, either here or on my tumblr bittodeath.tumblr.com. I don't know which pairing will come next there are still a lot, so a little vote perhaps: Daichi/Kuroo or Sugawara/Terushima? Please drop_by_the_archive_and_comment to let the author know if you enjoyed their work!