Day:3/30 (smut)

Prompt: Fantasy AU

Couple: M/M Kirishima (top), Bakugou (bottom)

Words: 1,584

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Although Kirishima was a dragon, he knows jack shit about them. He was born from an egg to a nearby tribe. Where a blond and a rather rambunctious woman picked him up and raised him as his own. He may not have been able to spend his time with his blood-related brothers and sisters, but he never found himself missing them.

His adoptive mother was named Mitsuki. But he just called her mom.

A couple of months after she adopted Eijirou, she naturally gave birth herself. It scared Eijirou, he felt that he'd be forgotten. But 13-month-old Eijirou didn't get the concept of shared love.

She named him "Katsuki". He was a carbon copy of Mitsuki, which admittedly, made Eijirou a bit jealous.

He got used to the tiny blond's presence. At first, he wouldn't talk to him and refused to share his toys with the obnoxious baby. But once Kirishima hit 4 and Katsuki hit three, they were inseparable.

Despite the connection, Kirishima never considered Katsuki his brother. It may be the biological fact that Kirishima could shift into a dragon and Katsuki could not. Or maybe a psychological thing. That told Kirishima that they were more than unlikely relatives.

-

Kirishima was 15 when he first felt it. He sat behind Katsuki, brushing his hair. When the blond turned to tell him something.

But they were close. So so close.

Kirishima's senses we're always heightened because he was a dragon. But he was able to smell him so well. He smelt like ash. Like it could burn his nostrils, but he couldn't pull away. The feeling was intoxicating.

Katsuki's face was too close. He could see the subtle rise and fall of his chest. The blond was saying something, he couldn't hear. He was too fixated on the way his lips remained slightly parted when he stopped speaking. Or how delicate his tongue looked when it pops out to run across his lips.

It took Kirishima about a minute to realize Katsuki stopped talking.

Katsuki's face was flushed when Kirishima looked up at him. They just stared at each other.

"What are you doing?" Katsuki asks.

Kirishima blanks. He could've responded with 'I don't know' or just kept himself silent.but he couldn't. He couldn't when Katsuki looked at him like that. With his eyes so open and questioning.

"Just looking." He responded.

Katsuki's face burned more "just looking?"

"Yeah. Just looking."

Silence.

"What were you saying again?"

Katsuki closed his eyes and pondered. Kirishima admired his eyelashes.

"I don't fuckn remember." He spoke. His voice was small.

Kirishima cleared his throat and looked down. "I'm tired... I think I'll head to my room."

Katsuki nodded and moved aside. He watched as Kirishima left and stopped at the doorway.

"G'night," he said.

Katsuki yawned.

"Night."

Kirishima firmly believed that that night flipped some sort of switch. The switch that controlled what he thought about everything.

It was almost like his world was flipped upside down.

He wanted to cry.

The feeling was overwhelming. He'd thought some things he shouldn't have. Or at least, some things that feel wrong.

So so wrong.

But the warmth of Katsuki's skin was far too reassurings and the feeling of his hair between his fingers felt calming.

He wished he could say he hated it more than he loved it.

And wanted it.

That night felt like years of unrecognized feelings rushed to him at once.

Fuck, he was so in love.

-

As much as she could, Mitsuki taught him everything she could about being a human, but when he shifted into his dragon form, he was on his own.

That, he thinks, was the reason why this rut scared him so much.

It may have been normal, it may not, but when Kirishima had his first rut at 22 It was surprising, to say the least.

He woke in a cold sweat. His heartbeat was unrelenting. He was unbelievably cold and craving a warm body alongside his own.

Kirishima had read some things about Dragon ruts but never looked into them. Beliving that because he was a human- Dragon hybrid, he wouldn't have to deal with them. Guess that was a mistake.
.
The room was smothering, and every breath Kirishima made burned.

After Kirishima turned 19 and Katsuki 18, they moved away from the tribe to essentially, become nomads. Now they kill beasts and catch criminals in this large village. They were going to move along again in about a month to become the heroes of another town.

Because of this, Katsuki hated  losing sleep. Once, Kirishima woke up at 11:00 to get something to eat and dropped all the cutlery in the drawer because he decided it would have been a good idea to rearrange them. Katsuki woke up. Make a long story short, he was pissed and Kirishima got an ear full.

If Katsuki isn't asleep and doesn't stay asleep by 8:30... someone's going to hear about it.

So, Kirishima feared that even the huffs of his quickened breaths could wake him up.

Kirishima sat up from his bed and groaned loudly. He could feel the weight of his dick heavy against his leg.

He touched it and grunted loudly in pain. He was inhumanly hard.

He went to stroke himself. But the movement a left a trail of painful heat down.

Kirishima wore nothing to bed but his shirt. Which- he was forever happy about.

He stopped it off and sat on his knees, tugging slowly at his dick.

The feeling was so deliciously painful. He could feel a new softness at the base of his dick, where he figured a knot would eventually form.

His panting grew louder as he came on his sheets. The resulting growl was loud as he tried desperately to keep himself out of his full dragon form.

He took a deep breath and growled louder. His dick just burned hotter. He stroked down again and could feel the soft area of his soon to be knot hardening.

His sweat was drenching his bed. He continued to fuck slightly into his fist. He moaned.

"What the fuck are you doing in there!" Katsuki shouted.

Kirishima honestly wasn't in his right mind to respond coherently. He just moaned in response.

Katsuki's voice quieted down.
"Are you okay?"

Kirishima grunted in response. Katsuki smelled damn good through that door. It's almost like he forgot how to speak, there was only one thing deep down inside him that screamed 'Don't let him in.'

But that tiny thing shattered as the door flew open.

Katsuki looked worried until his eyes landed on Kirishima. Sitting up with his knees on his bed. Still feverishly stroking himself.

Katsuki's face flushed, his eyes fixated on the sight.

Kirishima wanted him to leave. But he couldn't speak. He started at the blond and stroked quicker.

"You told me you wouldn't have a rut," he said looking shamelessly at Kirishima's hand.

The other didn't respond.

Katsuki looked at his eyes again. " do you need help?"

"Oh, fuck" is all Kirishima could say. He nodded.

Katsuki sat in front of him, as closely as Kirishima thought he possibly could. Kirishima didn't let go of his dick when Katsuki touched it. They stroked in unison.

Kirishima came with a shudder and a defining groan that made the walls vibrate. He's wings jutted out of his back just as fast as they were pushed back in.

"Fucckk" he muttered

Katsuki was prepared to go "your welcome" and leave to clean himself off, but Kirishima only began to stroke himself quicker.

"Lean back against the wall." He said.

Kirishima didn't immediately comply but a good three minutes later his moves, still stroking.

Katsuki tears Kirishima's hand away from his length. He panted and shuddered at the loss before Katsuki moved his head down and circled his mouth around him.

Kirishima's chest rumbled in an earthy moan. He forced Katsuki's head down and thrust his hips up. Katsuki gagged and fought for breath as Kirishima shot down his throat.

The Dragon let go of Katsuki's head and took a deep breath. He moved quickly, pushing Katsuki down and lining up to fuck him.

Katsuki froze. He figured things would end up this way it'd be a lie if he said this isn't why he offered to 'help' in the first place. But he expected to get some time to, Ya know, prepare. In hindsight that was a stupid fucking thing to think.

Kirishima looked down at Katsuki as if he were asking. Katsuki just grinned and nodded.

Kirishima eyes darkened. He began to breathe quicker.

"I'm gonna breed you so good." He moaned, pushing fully into Katsuki.

Katsuki screamed out, clenching his eyes.

Kirishima felt he couldn't choose his words m but if he could hed praise the hell out of the blond below him. He could feel his knot inflating with every push.

"M' gonna plug you up so nice soon" he muttered.

Katsuki moaned. "then fuckn do it"

Kirishima hand wrapped around the blond's neck. His teeth grow sharper and his wings jut out again as he comes. And Katsuki doesn't believe he's ever seen something that attractive in his life.

The color in Kirishima's face seemed to have returned when he looked down in horror

"oh, shit" he started.

Katsuki brought his hand up to the dragon's mouth.

"Don't say anything. Just enjoy it."

Kirishima noded "this is gonna take a while to deflate."

The other smiled. "Good."

An:I tried to make this like... Not insest... Sorry if I failed