Somewhat cracky NSFW #bkdk thread for @ya_boi_Diggles.
Humor fic. Incubus Izuku, human Katsuki, uh... I'm not even sure how to tag this. Izuku makes tea from Katsuki's sweaty clothes. Also his tail is an erogenous zone. ENJOY!
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Izuku was born an incubus. No, it wasn't his quirk. He was still sadly quirkless up until All Might passed his quirk onto him. Nope, he was just unfortunately born needing to live off of the secretions that humans gave. He looked almost completely human except for...

Well, he had a tail. It was a little devil's tail whip of a thing. And he also had tiny horns that he could hide under his curls as long as he left his hair wild enough. He usually had to keep his tail tucked under his pants so that people couldn't see it.

The world was accepting of physical differences because of quirks, but it would be too difficult to explain what Izuku was. There were plenty of mythological stories about incubi and succubi and Izuku's life was already complicated enough without the weird looks.

He needed to live off of secretions from humans. When he was really young that was easy enough. His mother could breast feed him and he was filled just like any other child. But eventually milk ran dry and it was too weird and Inko realized her son couldn't get proper nutrition.

He could consume human food but it only really provided him half the amount of energy he actually needed to be healthy. His stomach could only indulge in so much food, after all, and he could eat high-calorie food his entire life and be healthy.

Izuku's father was an incubus who had all but abandoned Inko not knowing that she was pregnant with their child. He had been looking for a quick fuck and Inko had suffered the consequences of that. So he was no help. The internet was what really helped.

Any secretions from humans would work for Izuku. This meant sweat, tears, saliva, and, yes, cum. The act of sex itself could sate Izuku's incubus appetite for a solid week (according to research) because of the physical contact and the amount of kissing involved.

But when Izuku was a kid this was definitely /not/ an option. And the only person who knew about Izuku's needs were his mother. All of the options were pretty grim.
Luckily his mother had always been a crybaby. One sad show and Izuku had half a bottle to sate him.

Izuku learned not to find this weird when he was younger. He only learned it was strange when he asked to lick a crying child's face for her tears and she had screamed at him and cried harder. His childhood friend Katsuki laughed at him for that.

Izuku also learned that tears had a... flavor to them. Izuku could taste the emotions the human had to cause the tears to flow. His mother's tears usually tasted sad - it was a numb kind of bitterness - but he'd had her happy tears too. Those were warm on his tongue.

Tears from laughter tasted like pop rocks made of sunshine. Happy tears were sweet and mellow. It was fascinating. Izuku wanted to try more but, well, he couldn't just go trying random peoples' tears.
He tried it once with Katsuki who had been proud but hurt and had cried.

He had just gotten beaten up, so Izuku kissed his bumps and bruises better and kissed his eyes to taste his tears before Katsuki had shoved him away, red-faced, and told him to stop. Katsuki's tears had tasted like green apples. Sweet and sour at the same time.

Katsuki actually had a habit of tasting sweet. Izuku had learned this when he had stayed over at Katsuki's house and Katsuki had thrown aside his dirty, sweaty shirt to go change in his room. Izuku had been desperately hungry - the kind of hungry his incubus side needed.

The draw of Katsuki's soaked shirt was too much. He picked it up and, after checking nobody was looking, pulled it into his mouth to suckle on.
It was /delicious/. The sweat of adventure and sunny days of childhood tasted like soda pop and candy. Katsuki tasted sweet.

It didn't matter what kind of sweat it was - anger sweat from Katsuki's tantrums, happy sweats from playing, sweat from resting in a room too hot - all of it tasted like some version of sweet. Like how each soda had different flavors even if it was all sugar.

Izuku quickly became addicted. More than once he had guiltily stolen Katsuki's clothing to take home and suck on. But when Katsuki began to complain that his shirts were weirdly stretched in places, he needed to think of something else.

Besides, the shirts were usually dry by the time that Izuku got them somewhere he could suck the sweat from them. So he came up with a new method that he took advantage of whenever he could even during the years when he and Katsuki weren't exactly on the best terms.

Boiling Katsuki's clothes made for a wonderful tea. To anyone else it might just taste like sweaty water, but to Izuku it was one of the most delicious drinks. In a way he was cleaning Katsuki's clothing and making something to help him live. It was a win-win situation!

He had explained to his mother what he was doing, which had made both of them panic for a while, before she agreed with red face that maybe that kind of stuff was fine. She bought him a good sized pot and a portable burner to warm it over.

Izuku and Katsuki weren't the closest of friends through middle school, but Katsuki didn't exactly hate him. Izuku still wanted to be a hero and Katsuki didn't like that, but other than shoving him around and discrediting his dreams he didn't really hurt Izuku.

They were close enough friends that Izuku could visit him, at least, and spend the night at times. His parents really liked Izuku and Izuku was willing to put up with Katsuki being a jerk of a middle schooler if it meant he got to drink his sweaTea.

But this was a terrible idea. A terrible, horrible, life-changing idea. Because one night Izuku had dragged one of Katsuki's sweat-covered shirts from his hamper while the boy was sleeping (he had memorized the smell of his stale sweat) and had made a tea out of it...

Only to realize there was a completely different taste to it. It had the flavors of happiness and frustration that Katsuki's sweat usually carried, but there was more. Something hot and spicy, like sweet curry, that had Izuku groaning with pleasure.

The more Izuku drank, the hotter his body became. A sweat broke out on his own skin, but he couldn't stop drinking. He usually liked to bottle some of it for later, but he couldn't do that here. Without his knowledge he had become unbelievably hard and his body ached.

Izuku had experienced arousal before. He was a normal teenage boy despite the sweat and tears drinking. But to experience someone /else's/ arousal was another story. He couldn't even control himself as his hand slipped into his pants and grabbed himself to begin stroking.

He tried to drink slowly, savoring the flavor, as he jerked himself off on Katsuki's bathroom floor. He didn't know it right away, but he realized this must be a sweat that broke out while Katsuki was touching himself. He couldn't taste anyone else's sweat in the mix.

That meant it could only be masturbation. And Katsuki had done it recently too because the sweat was stale but not terribly old. Did he do it right before Izuku had come over? He didn't know, but he was drowning in it. It didn't take much as he fisted his cock before he came hard

Izuku was left breathless from it and with some of the tea still left. He flushed and bottled it up, confused and concerned for how much it had affected him, and had cleaned his underwear before he had returned to sleep in Katsuki's room. That had been weird.

It wasn't the last time Izuku had indulged, though. He didn't find another sweat like that from Katsuki for a long time, so he made sure to keep his sweaTea on hand. It never failed to get him off. It was an aphrodisiac of the highest caliber.

He figured it was because he actually did have a major crush on Katsuki, but it was possible that all incubi felt like that when it came to sex. After all, incubi were known for being extremely sexual. Maybe Izuku was just having a late awakening. But he didn't really want anyone

He wanted Katsuki, but there was no way he could bring it up. Not with everything that was going on in their lives. And Izuku was pretty sure he would rather die than tell Katsuki he had been cooking his sweaty shirts and drinking the tea he made from them.

Unfortunately that was exactly how Katsuki found him one night in the dorm bathroom at midnight in their first year of high school. Izuku had been in the middle of brewing a new tea with the gym uniform he'd stolen from Katsuki's wash that day when Katsuki walked in on him.

Which by itself wouldn't have been that bad. Actually, no, it /was/ that bad. But it was made worse because Izuku was using the alone time to have, well, alone time. With some of the specialTea sweaTea that he had made from Katsuki's masturbation sock (that had been a lucky find)

The scene was set as such.
Katsuki: in the doorway, staring at everything.
Izuku's pot: heating with Katsuki's gym uniform in it.
Izuku: wide-eyed and staring at Katsuki with horror.
Izuku's tail: out.
Izuku's dick: also out.

"Deku... What the /fuck/?" Katsuki seemed genuinely baffled by what he had come across, which was rare for Katsuki. Even when confused he never looked /this/ confused.
Izuku had to think quick. The cliched "this isn't what you think!" wouldn't work here.

"I'm washing your uniform!!" Izuku cried, smiling nervously as he tried to surreptitiously tuck his cock away. Fuck, he could still feel the effects of the tea in him, though. His arousal wouldn't be going away soon with that flavor on his tongue.

Katsuki's eyes darted to the ladle in the pot doubtfully. There wasn't any soap nearby. It was just them, this pot, two water bottles, and Katsuki's boiling clothes. Izuku turned off the heat on the portable burner.
Katsuki was starting to get angry. "With a /ladle/?"

"I-It helps with stirring the water!" Izuku was panicking. His tail had darted to hide around the side of his body. His face was flushed red and he was sweating buckets now.
"You were jerking yourself off!"
"I had some free time while I waited!"

Katsuki stalked towards him now and grabbed the front of Izuku's nightshirt. The teen yelped as he was pulled to his feet. Katsuki was gritting his teeth now, eyes sharpening as he pointed at the pot and hissed, "Explain. /Now/. Are you the little ass who kept ruining my clothes?

Izuku held his hands up between them and avoided Katsuki's eyes. "N-Not on purpose! I..." Oh god, this was weird as hell, "You won't believe me if I tell you!"
"You think I even believe what the fuck I'm seeing right now? You jerking off over my clothes?!"

Izuku gave him an affronted look. "I'm not jerking off over your clothes! I'm jerking off /near/ your clothes. Which I'm cleaning!"
"Bullshit!"
"I'll explain!" He relented reluctantly. Katsuki released him and Izuku ran a hand over his face. He should've locked the door.

So he explained what he was and what he was doing. Which wasn't easy because how the fuck do you explain that sweat tastes differently to you? Katsuki gave him a dumbfounded look by the end.
"I don't believe you." He said bluntly.
"I knew you wouldn't." Izuku whined.

"This is just fake, ain't it?" He reached around Izuku to grab his tail. Izuku yelped, prepared for pain, but a completely different sensation ran through him. His tail was sensitive to begin with, but he had long since gotten used to it brushing around in his pants.

He didn't noticed the sensation of cloth against his tail anymore than he did when cloth brushed against his cock. But it was completely different when it was in someone's hand. It was a totally new sensation and Izuku's knees buckled a little as he gasped.

"What-?" He breathed. Katsuki didn't seem to notice as he yanked at it. Izuku moaned loudly, cock twitching in his pants. His hands flew to his mouth as he and Katsuki looked at each other with wide eyes. Izuku felt his skin heating up more. He saw sweat on Katsuki's face.

Katsuki's lips twisted into that sadistic smile that Izuku recognized from his childhood. Oh no. OH NO.
"What's this? It's actually real?" He gave another little tug on it. His hand slid along the skin. Izuku moaned again, body arching as he reached for Katsuki and grabbed him.

He trembled, paralyzed from Katsuki's grip, as he held onto his friend's shoulders for support. "Maybe you ain't lying about being an incubus... but that doesn't make you any less of a pervert." His fingers tangled the thin tail around them.

Izuku couldn't understand what he was feeling. This was almost as good as having his cock stroked. Was this the effect of the specialTea sweaTea along with the fact that Katsuki was touching him. He was stroking his tail with determination.

His hands bunched Katsuki's shirt in them as he whimpered, "I-I'm not a p-pervert! I had to-!"
"Sneaking my shirts away, sucking on sweat and tears, jerking off to the taste of someone's sweat? Sounds like a fucking pervert." Katsuki denied, grinning. He was having fun.

"K-Kacchan, please!" Izuku didn't know what he was begging for. His back arched, either trying to push his tail more into Katsuki's grip or presenting himself more. Katsuki yanked and Izuku cried out, tears running down his face.

Katsuki's breathing had picked up as he watched Izuku. "Are you getting off to this, shitty Deku?" He asked, voice thick. He swallowed. Izuku's eyes were blurry from his own arousal as he tracked the sweat. He wanted to lick it.
"N-No, it hurts..." He lied weakly.

Katsuki gave another sharp tug, twisting the tip around his fingers. Izuku sobbed, thighs trembling with the need to feel more. He could feel his orgasm building in him. Part of him was humiliated at the fact that he liked this. He wanted more.

"Sure sounds like it hurts." Katsuki mocked. His hand was unrelenting. He grabbed the back of Izuku's head and tilted it up for him to see. Izuku could barely see through his haze. His mouth fell open, breathing in the air thick with his desire. Katsuki's pupils were blown wide.

"Bet you want to get your tongue on me, huh? Like to taste of my sweat, you pervert? Have you tried to find clothes with my cum on them so you could boil those too?" Katsuki's smile was twisted. "That shit taste better to you? Would you wanna suck my cock?"

God, Izuku did want to do it. He wanted to swallow Katsuki down and choke on his cock if it meant he would get to taste him first hand. No matter how tasty the tea was, fresh was always best. And he /had/ found some of Katsuki's cum clothes before. It was what he was high on now.

"Well?" Katsuki asked breathlessly.
"Yes." Izuku whimpered. He was close. "Kacchan tastes amazing. It's my favorite flavor."
"Lick my neck then." Katsuki commanded. Izuku wasted no time as he wrapped his arms around Katsuki's shoulders to lick a stripe on his neck.

He groaned with desire as pure sweet curry coated his tongue. It was satisfying and refreshing at the same time. He lathed his tongue against Katsuki's throat, dipping down to kiss beads of sweat from him. Katsuki's hand never stopped even as the other banded him close.

"You're turned on." Izuku whispered as he drowned in Katsuki's essence. "Kacchan, do you like this?"
"It's cuz you're a fucking sex demon." Katsuki grunted even as Izuku grinded his cock to Katsuki's.
"Only for you." Izuku whispered, desperate and not quite in a sane headspace.

"What? Shit-!" Katsuki cried out as Izuku's hands clutched him close and Izuku came. He sobbed against Katsuki's throat, gasping as his hips stuttered against Katsuki. His tail twitched sporadically in Katsuki's grip before he went limp. Katsuki's breathing was labored.

Izuku was overwhelmed. His head was swimming with his and Katsuki's arousal. He could already feel himself stirring for a second time even though he was still erect. He felt like he could easily come over and over again. His body needed it.

He pulled his head back to gaze at Katsuki, a soft smile on his face. "I'll be a sex demon for you, Kacchan. Just you. I don't have experience, but I'll make you feel good." He slid to his knees before Katsuki, completely high on desire.

This seemed to snap Katsuki out of whatever trance he was in. Izuku grabbed the top of his tented sweatpants to pull them down, but Katsuki shoved away. He stared at Izuku with confusion. Izuku couldn't think straight as he questioned why Katsuki was moving away.

"You..." Katsuki's frowned twisted into a hesitant smile, "Holy shit, you really do get off on this. Are you even all there?"
"I don't know." Izuku admitted. Part of him was aware that he was being a little insane. He dug his nails into his palms.

Something complicated crossed Katsuki's face then. Izuku knew that look as well. It was the same regret Katsuki had when he realized he had gone too far with bullying Izuku. But Izuku hardly cared about that at that moment. He crawled towards the teen. "Should we continue?"

"Fuck, I didn't want to do it this way." Katsuki muttered to himself, hand covering his mouth. He was red. Izuku's mouth opened, pressing as kiss over Katsuki's clothed cock. Having sex would sate him for a week. He'd been dreaming of having it with Katsuki since forever.

"I want you." Izuku promised. "I really like you, Kacchan."
Katsuki cursed loudly and hauled Izuku to his feet. Then he pulled him into Izuku's first kiss. He blinked as he tasted saliva for the first time. It wasn't sweet like Katsuki's sweat.

It was all heat. It was spicy and mellow at the same time. Addictive like the burn of alcohol. Izuku whimpered as the kiss deepened, his hands running up Katsuki's chest. He could see how incubi were seen the way they were if sex felt anything close to this. He felt amazing.

It seemed to take all of Katsuki's self-control to yank away from Izuku. He panted and put distance between them as he held his hands up to keep him away. He glared and pointed as he said, "We'll talk when you're not... like this. You're fucking drunk."

"I'm not drunk!" Izuku assured him.
"High! Under the influence of... sweat! I don't fucking know, but you're not thinking straight! And it's affecting me too! Just... I'm going back to my bedroom and you'd better not follow!" Katsuki sounded pissed off about it.

"But-!" Izuku tried to protest, but Katsuki turned and fled. Izuku had never seen him run away before, but this definitely constituted. Izuku whined and sank to his knees again, cock throbbing in his pants. He would be grateful for it when the effects of the arousal wore off.

But for now he could only lament how Katsuki had gotten away as he pulled his cock out and continued where he had left off. Judging by how he felt, it would be a little while until this wore off. Izuku could still taste Katsuki on his tongue.

His chances weren't bad, though. Maybe once they'd cleared their heads they could talk. Izuku already couldn't wait for tomorrow or to get another taste of Katsuki. If that's how he tasted now, how would his cum taste?
Izuku was an addict and Katsuki was his favorite drug now.

(End!

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