Explicit M/M sexual content ahead, all tags on the end of chapter note

Obito woke up to his phone ringing, his hands fumbling through his nightstand knocking random stuff all over it until he felt the shape of his phone and somehow in his sleepy state managed to press the correct buttons to answer the call.

"Hello?"

"Obito!"

"Kakashi?!" He immediately reacted to the voice he loved so much. All sleepiness was gone when he heard the desperation in Kakashi's voice and he scrambled trying to sit on his bed.

"Obito, please! Please! I need you!" Now that his mind was clearer, he could hear that the drag in Kakashi's voice wasn't worry or fear like he thought before, thinking maybe something awful had happened. No, it was lust, desire, need. Obito's own cock got half hard just by hearing Kakashi's pretty moans.

"Is your rut here, 'Kashi?" Obito asked, trying not to sound too eager, after all, he knew rut, he knew it could be hard even under medication. He scrambled to his feet trying to change clothes while talking to Kakashi.

"Yes! Obito!"

"How are you feeling, babe?"

"I need you! I need your knot! Please!" Well, his jeans weren't gonna close anymore after that horny moan.

"I'm coming to you. Did you take your pills?"

"Yeah, but they're not working."

"How long ago?" Obito asked, looking at his watch on the bedside table, it was 4h30.

"Like, at four?"

"Ok 'Kashi, you'll feel the meds any time now, ok? I'm catching a cab and I'll be there in fifteen minutes, ok?"

"No! Faster! I need you now!"

"It's ok, love, I promise I'm coming and I'll stay with you all day, I promise."

"Ok… I'll wait…"

Obito's alpha instincts kicked in, telling him to care for his partner in heat and his voice was softer. "Yeah, good boy, drink some water, ok? Take another pill like Rin said if you don't feel any better."

"Ok… I miss you Obito…"

"I miss you too, love, be there in fifteen."

On the cab he sent a message to his boss telling him he wouldn't make it work today, and it was a good thing he and Kakashi registered their relationship on the human resources for this type of thing. This was the first rut they would spend together since they started having sex. He had a rut last month but Kakashi didn't help him since they weren't intimate like that yet. Was it weird that he was excited about this? Sex with Kakashi was always earth shattering, mind blowing every time already, what about on rut? He was morbidly curious. He sounded so needy on the phone, Obito couldn't help but imagine how he was right now. It was the longest drive in his life to get to Kakashi's apartment.

"'Kashi? Are you there?" Obito could already smell Kakashi's pheromones through the door, driving him insane.

The door opened and a hand grabbed him by the collar pulling him into a barrage of the best scent he ever felt in his life. Kakashi slammed Obito's body against the wall, kissing him desperately and Obito's cock was now fully hard at the touch of his boyfriend. Obito pushed Kakashi onto the opposite wall knocking the breath out of his lungs, his lips parting for Obito to kiss him harder and deeper. He toed his shoes off and took off his jacket, letting it fall to the floor, never breaking contact with Kakashi's lips. Kakashi's hands were gripping where he could, his hair, his shoulders, his clothes, while Obito trapped him between his arms, his tongue was aggressive inside his mouth.

Soon enough Kakashi was moaning loud, his whole body spasming and Obito knew this, this was how Kakashi's body looked when he was coming, but… there was no way this was it? They were just making out, Obito hadn't even opened his pants yet, or touched any of Kakashi's sensitive points, so why was he feeling warm cum spilling from Kakashi's cock trapped between their stomachs staining his t-shirt?

"Obito!" Fuck he loved how his name sounded on Kakashi's lips when he came begging for him.

"Did you come for me, love?"

"Your mouth, Obito… is so good…" Kakashi slurred his answer as the trembling subsided.

Obito dragged a hand through the fabric feeling the warm wetness covering his fingers, he brought it up to lick them over, fuck he loved Kakashi's taste, everything about him was just perfect. Kakashi's tongue came to lick and suck on Obito's cum covered fingers too, moaning at his own taste. Obito then pushed the fingers inside and his boyfriend obediently took it all in. God, Kakashi was so submissive right now, where was all the spunk, the fight, the hot and cold? He guessed that rut made him relaxed and compliant, even needy, yeah, definitely needy, Kakashi was already humping his thigh again. Though Obito loved this submission just as much.

Obito hooked his hands under Kakashi's knees to carry him to the bedroom, otherwise they'd end up fucking at the entrance. As soon as he did so, he felt wetness in his clothes, and noticed it was Kakashi's cum still dripping from his cock. Obito's clothes were now ruined in the best possible way.

He threw Kakashi on the bed and took off his t-shirt, throwing it on the floor somewhere. Kakashi was only in a baggy t-shirt, no shorts, no underwear, dick standing proudly, big and hard, his knot only a bit swollen. Obito noticed the shirt was one of his, the white ones he wears under the dress shirts, and he wondered if he'd forgotten it over at Kakashi's. He tried to remove the now see-through t-shirt, because of how wet it was, covered in sweat and probably cum too, but his boyfriend crossed his arms over his stomach not wanting to let go.

"C'mon babe." Obito cooed against his mouth trying to pull it again but Kakashi only whined.

"Smells good! Obito!" His heart felt like exploding, Kakashi was finding comfort in spending his ruts with Obito's smell? That was so sweet, in a horny way.

"C'mon 'Kashi, you have the real thing now..."

"No... I love this shirt..."

"I'll give you another one, ok? I promise." Obito tried to say it as gently as possible, but Kakashi still shook his head.

"This one has your sweat in it..." Was Kakashi wearing... one of his dirty shirts? Why didn't he grab a cleaner one? Did he go get it from the dirty laundry hamper? Rut really made you do strange things.

"I promise I'll give you one of my gym shirts next time." Kakashi had the guts to moan at that. He fucking moaned at the thought of Obito sweaty from gym, his hips grinding up against Obito's, honestly, and it was nice to be desired like that. "C'mon 'Kashi, I promise to come all over your face, then you'll get my smell on you, how about that?"

Kakashi moaned again and Obito was getting addicted. He forgot the shirt for now and focused on kissing those pretty lips, pressing their hips closer together. He was still wearing his jeans, even if Kakashi was naked, and Obito didn't give two shits about it, the friction was amazing, his boyfriends hands and nails digging on his skin, squeezing him tightly, shivers coming from his dick. Everything was perfect. And Kakashi's smell, oh his smell was divine. There was an edge to it, it was different from his regular scent and his usual arousal scent, it was a bit like the later, but sharper and a hundred times more intense and Obito wanted to drown in it, bottle it and drink it, he wanted to sink his teeth on Kakashi's neck and bite a piece off his delicious skin, chew on him and eat him whole.

Kakashi came once again as they were kissing and making out and Obito marveled at how sensitive he was. Chest arching out from the bed, eyes shut tightly, more cum spilling between their stomachs. With Kakashi's new climax, Obito could feel his vision become tunneled, darkening on the edges. Only the man he loved mattered now.

"You're so sensitive, love. What am I gonna do with you?"

Kakashi kept whimpering, Obito guessed he was no longer able to articulate words or human sounds, only animalistic ones. He moved down to suck on his nipples, he knew how much Kakashi loved it, especially when he was harsh, biting and pulling on them. Obito pushed the shirt up and sucked on the right side as the man under him thrashed around and moaned, but he didn't relent, he kept going. The skin of his nipple was so soft, it was thin and sensitive, Obito could just live the rest of his life right here, sucking on them, and he'd die a happy man. He bit the whole nipple harshly and Kakashi yelled. Looking down on his work, there were teeth marks around it, his alpha fangs making a deeper dent on the soft flesh. Obito resumed the sucking, lick, pulling, and when he bit down hard on the very tip of Kakashi's nipple, a seizure coursed through his boyfriend's body, more cum wetting their skins and the sheets.

"'Kashi, my love, how many times is it? Three? You already came three times?"

"More than three…" Kakashi managed to breathe out in a shaky exhale as he rode the last bits of his more recent orgasm.

"More?"

"Before you… I jerked off…"

"Oh really?" Obito wanted to tease Kakashi, but his voice came out gentle and affectionate, his alpha instincts telling him to care for his fertile partner in such a crucial moment, because he was suffering, and only his cock could help him.

"Your shirt… your smell…" Kakashi must have lost the thread of their conversation because he was once again moaning and raising his hips, offering himself to Obito, presenting himself like an omega in heat.

"How many times have you come, my love?" Obito brushed stray strands of silver hair from Kakashi's brow, damp with sweat, those lovely eyes lost, his hard again cock pressing between them.

"Don't know… I'm ready… my ass is ready… for you… for my alpha…" Obito moaned at those words. Kakashi must've felt very impatient while waiting for him.

"Is it babe? Let me check too. I don't wanna hurt you." Obito sucked on his middle finger and inserted it easily on Kakashi's hole, no resistance at all, and his cock twitched in desire.

"Obito… would never hurt me… my love…"

His heart clenched at such a demonstration of trust, and Obito wanted to believe that. No. Cross that. He was gonna make that sentence his ultimate truth. He would work every day, for the rest of his life, until his dying breath, to never hurt Kakashi, only to make him happy. He loved this man, and he would devote his whole life to him.

"It's ok babe… let's get you wet." Obito fumbled around looking for the lube bottle impatiently, finding it on the floor by the bed, together with a purple dildo and he felt a smirk come to his face. Kakashi must be very ready indeed, but still, the dildo was smaller than Obito's own cock.

Obito got rid of his pants finally and poured lube over his achingly hard cock hissing at the cold and gave it a few pumps to cover it all. Kakashi was shuffling anxiously before him. "Fast… love, please… your cock…"

"Shhh love, I'll fill you up in a second ok? C'mon open your legs for me babe."

Kakashi obediently spread his knees wide and pulled on his ass cheeks and Obito almost came all over him. He was so submissive today, what happened to that Kakashi that had to push against and fight him on every little thing in bed to make sure that Obito was a worthy alpha before letting him fuck his hole? That was the power of hormones he guessed. And his own hormones too, were playing a trick on him, as he was starting to feel more and more like his rut was coming onto him too. He could tell by his blurry vision, distorted sounds, the way his knot prickled at him as he watched Kakashi presenting himself on a silver platter for Obito to fuck him.

"Obito… please, please…"

Obito put the head of his cock on Kakashi's soft, soft hole and pushed inside, only warm, welcoming wetness and pressure, no tension whatsoever, almost as if Kakashi's body was built to take him. He didn't stop until he bottomed out, and all his cock, including the beginning of his still small knot was inside the man he loved.

And at that, Kakashi came a fourth time. His muscles clenched and flexed around Obito, and he felt like his cock was being massaged, as if his boyfriend's hole was trying to milk him out. Cum continually shot up Kakashi's spasming cock yet again that night, and Obito wondered how he still had anything in him, by now surely his cum should already be thinning, becoming watery and releasing at smaller volume. But not Kakashi, not his fertile, perfect partner, who still kept spurting cum like he wanted to impregnate an omega himself. And wasn't it a shame that no one else in the world would ever have him the way Obito did? That Kakashi's big alpha cock, full of milky cum, attesting to his viability as a partner, would go to waste, because all her ever wanted, all he ever needed was for Obito's own alpha cock to fuck his cum inside him and impregnate him.

"You're doing so well, my love…" Obito caressed Kakashi's legs and sides as he finished coming while moaning his name loudly. "Shhh, you're doing great…"

"Obito… please…" What was Kakashi even asking anymore? Did he know?

"You came as soon as I put my cock inside you, did you miss me, babe?" Obito continued to trace soothing caresses over Kakashi's beautiful skin, his cock still not going soft after yet another release.

"I missed you so much!" Kakashi whined cutely, and Obito leaned down to place small pecks around his face.

"I'm here, my love. I missed you so much too. I wanted to be here for you, for your rut. I want to help you, babe."

"I love Obito…" Kakashi whimpered under the sweet, light pecks that Obito was littering his face with, giving a few kitty-like small licks against Obito's face. So cute, so precious.

"You're so pretty my love, my darling, I love you so much."

"Oh, yeah! Obito, keep talking!" Kakashi moaned and Obito could feel his arousal from the still hard cock trapped between them and from the way Kakashi's hole was twitching around him.

"My gorgeous boyfriend is doing so well. You're taking my alpha cock like a champ aren't you?" Kakashi nodded repeatedly and moaned a yes that got a smile out of Obito. "And now you're here, warming my cock, waiting for me to fuck you, I promise I will my love, I'm gonna fuck you so much, I'm gonna pump your belly full of my cum, I'll make sure you get pregnant with my baby tonight."

"Oh Ob-hic bito-o!" Kakashi moaned again and he was now hiccupping. Obito had no idea how this was even possible, because they were both still, he was lazily draped over Kakashi, resting his weight against him, not moving at all.

"You're such a good omega to me, I really lucked out with the best boyfriend, such a strong alpha that I turned into such a fertile omega." Obito was still pecking Kakashi's cheeks and lips here and there in between sentences. "And you're doing your best for me, aren't you? Being such a good boy, a good omega for me. Letting me knot you, I know it's not easy, babe, I know it's big, but you take it so well, you're doing amazing by satisfying your alpha, my love."

Kakashi was shivering all over, as if his muscles were cramping after running a marathon. Though he still wasn't coming, he was very close, and Obito wondered if he could make him come only with his words.

"And I know your heat is hard on you, my love, I'm gonna make it alright now. I'm gonna fuck you until you're satisfied, until you know for sure that I bred you. I'm gonna have to cum inside you and then plug you up, not even one drop will come out. I can't waste all the work my omega is doing, right? I'm gonna knock you up my love, can you be a good boy and carry my pup inside you? My love, my omega…"

Kakashi finally came after all those sweet words. The constant shivering became even harder and then he was thrashing under Obito, cum spilling yet again, flooding the sheets. By then, Obito's own words got to his brain, and maybe Kakashi's breeding kink was rubbing off on him, because by now he decided to make good on each and every one of his promises to his love.

He didn't remember much after that. The rut that he'd been feeling creeping up on his mind took over. There were flashes and sensations. Moments of calm, moments of storm, he had no idea of the concept of time and space, and everything was Kakashi from then on.

At some point he got thirsty and they moved to the living room for him the drink some sports drink, all the while fucking Kakashi against the floor, drops of the beverage rolled down his throat and Kakashi licked them as if that was his font of water. Obito half spit, half kissed some of it into Kakashi's mouth, thinking he could use some hydration too, from how much he came.

They'd be fucking over the kitchen counter and then next thing he knew, they were sitting on the table, completely naked, Kakashi on his lap still impaled by his knot that hadn't died out, and they were stuffing their mouths with potato chips, no cooking, no chopsticks, just animalistic instincts taking over. And even that would become fucking again as he grabbed on each side of Kakashi's slim waist and pulled him up and down his cock.

They slept whenever and wherever, almost always connected by Obito's knot inside Kakashi, be it on the bed, the couch or the floor. Obito would wake up to Kakashi pressing his ass against his cock, getting off all by himself. And at this point there was no need for lube any longer, Obito came so much inside Kakashi already that he was always soft and wet and it was better than any lube.

Baths were necessary but also an excuse for fucking some more, their soaped skins sliding even better together than their sweaty skins. He would command Kakashi to present himself for his alpha, and he'd turn around, put his hands on the bathroom wall and lean down, presenting his asshole for fucking, and so Obito did. Fucked him hard and fast as water fell down on them, Kakashi wasting his cum pitifully on the floor, his beautiful moans reverberating on the small space driving Obito insane.

And whenever Obito unplugged Kakashi's ass when his knot deflated, copious amounts of cum ran out freely, down his thighs, wetting the floor and that only made Obito want more. He would kneel and eat out his ass, eat his own cum together with Kakashi's taste and then get ready to pump him full with more.

They were trapped inside of a loop of positive feedback between each of their ruts for at least four days. At least until on a Sunday Rin knocked on Kakashi's door to collect his weekly exams and came to find the scenery of war that was his apartment. Both Obito and Kakashi refused to feel ashamed, but they did agree for a change in approach for both their medications. Obito didn't support it, for him, he'd die fucking Kakashi until his last breath, fucking the love of his life until death, and Kakashi said as much as Rin chastised them, pointing a scolding finger to their faces as they covered themselves with a blanket.

Obito checked Kakashi's neck and for some miracle they didn't bond, though some very nasty bites circled the area like some sort of bloody necklace, and he felt at the same time happy that even in his mad state of mind he was careful not to bond Kakashi, and disappointed that he didn't do so. Kakashi was his, only his, nobody else could lay a hand on him. He had no idea how bonding worked between alphas, or between an alpha and a dualsex, but it didn't matter, Obito would make Kakashi his even if they had to mate and bond every day to keep the marking on his neck. He smiled at that, and he was already making plans of booking two-weeks-long vacations for them for their next rut.

Sexual tags: sex during rut, rut triggers the other's rut, sweaty smell kink, multiple orgasms, dirty talk, praising kink, breeding kink, nipple play, knotting, is it mind-break if they're both losing their minds?, sex marathon, cum kink, free use kink

You know, having to put these tags here is making me sound like a pervert, which it's not wrong, but hey! I don't like being called out like that!