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Of Cum and Demons

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Kirishima yawned and hummed, still super snuggly in bed. The mattress was so comfortable, and the duvet and sheets wrapped around him were like the perfect cocoon. He stretched--or tried to. His wrists were being held down.

It took a few seconds for him to register the being on top of him after opening his eyes. Honestly, he probably should have noticed when he woke up, but he stayed up late, and honestly, who was that aware when they first woke up in the morning?

The man on top of him had short blonde hair with an undercut and piercing red eyes.

Okay. That’s not natural. Kirishima’s own eyes were light brown. In the right light, they sort of looked kinda red. Maybe. He liked to think they did, anyways.

The red eyes, though, weren’t the strangest thing about the man. After all, he could have been wearing contacts. It wasn’t that odd seeing people with fake eye colors anymore.

No, the oddest thing about him was all of the strange symbols and lines inked into his pale skin in black and red and the sleek, black horns jutting from his head. He had six of them that Kirishima could see.

The two largest were at the front of the man’s skull and curved backward from above his temples. Behind them were horns that got consecutively smaller until they vanished among his messy locks.

He was fucking gorgeous.

A tail swished behind him, long and black with bright orange patterns on it. The tip of the tail had some wicked spikes on it, and Kirishima swallowed hard, hoping he wasn’t about to get impaled.

As his gaze returned to the man’s face, he tried not to stare at the man’s chest and tight, toned abs. It was a struggle, though.

Cue being a gay disaster.

“Um… hi?”

The man scoffed. “ Hi? That all you gotta say?”

“Well, I mean… I just woke up.”

It was a good excuse, right? Well, as good as any that he could muster, at any rate.

Another huff, though the man seemed less annoyed this time.

“Who, um… who are you? How’d you get in here?”

“‘S more like it, shitty-haired moron.”

“Hey!” Kirishima pouted. “Look, man, if you’re gonna come into my house and insult my hair, I don’t think we can be friends.”

“...friends.”

“Yeah. Friends.”

“A stranger appears in your house, in your bed , and you’re willing to become friends with them?”

“...sure, dude. Why not?” He beamed. “But, um, maybe you could move? You’re sort of cutting off the circulation to my legs. And I’d like it if you actually told me what you’re doing here.”

The man smirked, showing a row of sharp, dangerous teeth, though he did adjust his weight, letting blood flow back into Kirishima’s thighs. “You’re under contract, shitty hair.”

“...um?”

“Someone close to you died recently, right?”

Kirishima nodded slowly. “Oh, yeah. Um… my… my aunt.”

He tried not to think about losing her. She’d been one fucking spitfire--not the type of person you wanted to dick with. Most of his family was sweet. She’d been the opposite of all of them.

The woman had a chip on her shoulder the size of the goddamn Earth itself, and she never trusted or liked anyone.

Well, except, for some fucking reason, Eijirou.

For whatever reason, she liked him enough to treat him with respect and love. It had made him feel special, and he’d grown really close to her.

Then, she’d been diagnosed with stage five liver cancer.

She died two weeks later.

The man smirked and leaned in, a long tongue dipping out from between his teeth to lick along Kirishima’s jaw. “Right. Well, this aunt of yours had it in good with the big boss. She offered him a deal.”

Kirishima cocked his head to the side; the tongue licking at him didn’t bother him. No, he was more confused about whatever the man was talking about. “What sort of deal?”

“She offered another soul--a purer soul--to take her place. In exchange, she wanted to ascend to heaven.”

His heart fell. “It was me, wasn’t it?”

The demon chuckled. “Not as dumb as you look.”

“Why would she do that? I… I thought she loved me…”

“Tch. Love is a human construct. When you die, it doesn’t matter anymore.”

“That’s not true!”

The demon snorted. “Doesn’t matter. What matters is that she traded your soul for hers. You belong to me now.”

Kirishima bit his lower lip, trying to figure out what to say or do to get out of this mess. He didn’t mind the hot demon sitting on top of him, but he didn’t really want to go to hell when he died.

Besides, being traded by his aunt hurt . It--

“Stop thinkin’ about it so much, goddamn,” the demon muttered, leaning in and kissing up the column of Kirishima’s neck. His tongue dragged across his throat before wrapping around it.

Heat seared from his saliva, and Kirishima cried out. “Hey! That hurts, man!”

The demon couldn’t exactly respond with his tongue looped around his throat, but when he pulled away, he said, “Good. You belong to me. Gotta make sure everyone knows it. The last thing I want is for some wayward demon to think you’re up for grabs.”

Kirishima struggled a little, but it was only half-hearted. “What did you do to me?”

“Nothing mortals can see,” he replied.

Suddenly, two more arms appeared. The demon still pinned him down, but the other two hands held a shiny mirror up, showing him the black and red marks around his neck. They looked like runes, but they wrapped all the way around his throat.

Kirishima’s eyes widened. “Oh…”

The mirror vanished, but the double arms remained. The demon ran his black nails along Kirishima’s sides, eyes darting down to watch the way his muscles twitched.

“Such a beauty. I had to defeat hell’s finest warriors to get you, you know,” he murmured as he traced the dips and rises of Kirishima’s ribs and trailed inward to his abs. “It wasn’t easy.”

Kirishima’s throat was tight. He didn’t know what else to say, so he just stayed silent, waiting.

The demon leaned in. “I’ll protect you,” he whispered against Kirishima’s ear. “I’ll treat you well and give you a palace to run and call your own. You’ll be a prince among hell’s finest royalty. You’ll rule my quarter alongside me.”

He shivered at the words.

“All you have to do is be mine. Do what I say. Adhere to my every whim, and you will know nothing but pleasure after death.”

Kirishima swallowed; the spit clung to his dry throat. He managed, “And… and now? While I’m still alive?”

The demon chuckled, still rubbing and touching him, though his hands inched toward Kirishima’s nipples. “Do as I say now, and I’ll protect you here. You’ll have a long, happy life, so long as you’re mine.”

He closed his eyes and exhaled, the breath shaky.

God, he’d been alone for so long.

It was so hard finding someone who wanted to care about him, someone who hadn’t just sought to take advantage of his kindness, someone who he could actually call a partner.

It was so fucking tempting.

When he opened his eyes, he murmured, “If… if you’ll be my boyfriend here, on Earth… do things with me, go on dates? I’ll… I’ll do whatever you want.”

The demon hummed and pulled back. Crimson light flashed through his eyes, and Kirishima could have sworn he saw the fires of hell itself reflected in them.

“Not that you have much of a choice,” he replied, toying with Kirishima’s nipples, “but I’ll adhere to your terms.”

“Y-you have to respect me, though.”

“Oh?”

“Y-yeah.” He cleared his throat, trying not to fall into the desire welling up inside him from the demon’s touch. His nipples burned, but in a pleasant way. “When… when we’re around others.”

“But here?”

The redhead’s eyes rolled shut and he lifted his hips. His dick was already hard. He’d been turned on for the last several minutes, but now that the demon was toying with his nipples, he couldn’t resist the urge to thrust and find friction.

He couldn’t concentrate long enough to answer. The burning pleasure in his chest made him pant and gasp.

The demon leaned forward and rasped, “Here, you’re my cum dumpster. My perfect little bitch to breed. Got it?”

He nodded.

“Tell me you understand.” The command was firm, heavy, but not unkind.

“I--I understand,” he gasped out.

The demon smirked and pulled his fingers away. His second set of hands wandered Kirishima’s body again, groping and squeezing everything from his pecs to his hips and thighs.

One even worked around and grabbed his ass, kneading the flesh.

“From now on, sleep naked. I dislike you being dressed.”

Kirishima nodded. “Y-yeah. Okay.”

All he was wearing was a pair of loose boxers, but okay. Yeah, he’d absolutely sleep naked from that point on if his lover commanded it.

The demon wasted no time tearing away Kirishima’s boxers and laying him bare.

“Look at you,” he growled. “Such a pretty, perfect specimen. And you’re all mine…”

He finally released the redhead’s wrists and pushed Kirishima’s thighs apart, his tail twitching and swaying behind him.

“Oh, um… what’s your name?” he asked, leaning up on his elbows and watching as the demon slid between his thick thighs. If he didn’t ask now, he’d forget.

Those hellfire eyes darted to him, holding his gaze in silence for a time before the demon murmured, “Katsuki.”

“Katsuki,” Kirishima whispered, trying the name out on his tongue. “Wow. It’s… such a pretty name for a demon.”

He squeezed Kirishima’s thighs. “And yours, my pet?”

“...Eijirou.”

Eijirou ,” he repeated. Then, “If you ever have need of me, and I am not around, you can call my name twice. I’ll appear.”

The redhead nodded. “Even… even if you’re in the middle of something important?”

Katsuki inched upward before leaning in so close that his searing lips brushed over Kirishima’s. “You are worth more to me than any of the trivial shit I deal with in hell. If you call for me, I’ll answer.”

“What if I’m just horny?” he asked, wiggling his eyebrows and grinning.

A devilish smirk crossed the demon’s face, and his four arms wrapped around Kirishima’s thighs before yanking him down until his ass was flush with Katsuki’s crotch.

“Then scream my name, and I’ll come fill you until you can’t fucking walk.”

He shuddered at that. “And… if I just want a kiss?”

Those lips barely rubbed over his. “Then I shall grant you one, pet.”

Kirishima’s eyes met Katsuki’s and he leaned up, hopeful.

The demon met him, and the searing kiss sealed his fate and the contract binding him. Kirishima wasn’t sure how he knew it for sure, but he did; and he honestly didn’t mind.

He slid nervous hands up Katsuki’s tight, toned body. The demon’s hips were narrow and small, but they tapered into wide shoulders and a firm, strong back.

His fingers traced over bumps in the demon’s skin, but he opted not to ask. Some felt like horns, but others seemed to be scars.

Later.

He’d ask about those later.

Right now, he wanted the demon inside of him. He wanted his lover to take care of him, fill him, use him until he could barely breathe.

Katsuki shoved Kirishima down, kissing him deeper and licking into his mouth with his impossibly long tongue. He sucked on Kirishima’s lower lip before grinding forward.

Then, all too soon, the kiss ended.

Kirishima repressed the urge to whine for more as his demon traced kisses down his neck and chest. Everywhere he kissed and bit, small dark runes expanded outward. They circled around Kirishima’s body, forging a contract that none could undo.

Soft whispering echoed in Kirishima’s head, but he ignored it. Someone laughed.

His eyes drifted shut as Katsuki worked lower and lower before he lifted Kirishima’s hips and spread his ass cheeks with two of his hands.

The other two trailed upward. One rubbed Kirishima’s right pec, groping and squeezing. The other lightly encircled his neck, squeezing.

“You… won’t kill me, right?” he managed, hand flying up to touch the hand on his neck.

Katsuki looked up from where he’d been leaning in between Kirishima’s thighs. “No. I cannot kill mortals. I’m not a reaper.”

“O-okay.” He slowly released Katsuki’s hand.

“You’re mine, ” the demon said firmly. “You will live a normal mortal life, safe from all harm, then you will become my mate in hell for the rest of eternity. That is the deal.”

He nodded. “Okay.” That time, the word sounded firmer. He’d just… he’d needed to know, to make sure he wasn’t going to accidentally leave people behind if sex got too intense.

Becoming beholden to a demon was one thing; he didn’t mind that. But losing out on his life, missing his family? Yeah, he wasn’t interested in that.

Katsuki’s fingers tightened around his throat. One of the hands on Kirishima’s thighs moved, and he pulled down the charcoal gray harem pants he wore.

It was the first time Kirishima had actually paid attention to what the demon was wearing. Turned out, it wasn’t much. His chest was naked, red barbells piercing his nipples.

The hem of the pants dipped low, and Kirishima’s eyes widened.

A big dick, he could have handled. Even two dicks wouldn’t have been much of a surprise, considering who he was about to fuck. What he saw, though, was beyond anything he could have imagined.

Katsuki had a thick dick all right. It was curved and erect, and he was pretty sure he saw some piercings glinting along the underside. What surprised him, though, were the two black and red tentacles that arched up from under Katsuki’s penis.

They were slick and dripped with a clear liquid.

“Holy shit,” he whispered.

Katsuki smirked, angling his hips forward as his hand tightened around Kirishima’s throat. One tentacle slipped inside Kirishima’s ass, the slippery substance on it lubing its entrance.

He yelped, hips stuttering upward and dick bobbing against his stomach, as the tentacle slithered deeper, slowly widening him as it fucked in and out of his ass.

“Holy shit,” he repeated, eyes wide as he gaped at the ceiling. “Ooooh, holy shit, holy shit, holy shit .”

Hands roamed his body, pinching and rubbing and exploring as the tentacle inside him searched and writhed. It rubbed over his prostate, and Kirishima’s jaw dropped in a silent cry as pleasure roared through him.

Katsuki’s hand never once left his throat, hanging on and sending shocks of pleasure jolting through the redhead every time his fingers twitched and tightened.

The second tentacle wrapped around his dick, rubbing along the full length before sliding upward and massaging the head.

He grabbed the sheets, fisting them and biting his lip to keep from screaming as his demon lover stroked him inside and out. Sensation welled within him, and he moaned as clear precum dripped from the tip of his cock, mixing with the fluid the tentacles secreted.

Katsuki leaned forward, grinning, the expression predatory and demonic. His hellfire eyes glimmered with lust and desire.

“You’re mine , Eijirou.”

He couldn’t even nod. Drool dribbled from his lips, and he twitched, thrusting wildly in hopes of peaking. Bliss welled inside him again and again, but the orgasm didn’t quite come.

He was so fucking close, though.

Just a little more… a little more, and he’d--

And then the tentacle in his ass slipped out.

“N-no! C-come back! Please!” he begged, tears in his eyes. Shit, he was so fucking close . He just needed a little more! Just needed enough to get him there! “P-please! I need--”

“I know what you need, pet,” replied Katsuki, and he angled himself, the thick head of his cock pressing against Kirishima’s open, wet asshole.

Kirishima cried out and tried to thrust downward.

His demon hissed softly, “So impatient.”

“Please!” he sobbed. “I--I want you! Please!”

“Want me to fill you up? Breed you?”

“Yes! God, yes!”

Katsuki hummed and pushed in. The tentacle that had been inside Kirishima joined the other one, sliding around his cock and pumping him off as Katsuki’s fat cock filled him.

The redhead’s voice stopped working.

His back arched.

He’d never felt so full before, and he never, ever wanted anyone else inside him again.

“Good pet,” whispered Katsuki. “Fuck, you’re so beautiful when you cry. I knew you would be.”

Then, without warning, he pulled out again before thrusting back in. The pace he set was rough and intense, enhanced only by his hands grabbing Kirishima’s hips and keeping him still while he fucked into the mortal.

His balls slapped against Kirishima’s ass, heavy and ready to dump their load. Katsuki’s third hand reached up to join the fourth around Kirishima’s neck.

He’d probably bruise, but he didn’t care. It felt amazing. So good. So fucking good.

Katsuki fucked into him harder and faster, his tentacles slipping and winding around Kirishima’s dick, dragging precum out of him. One wrapped around the base of his cock while the other pumped him.

Balls slapping into him, dick filling him, tentacles wrapped around his cock, working him over and over again--it was almost too much. He sobbed, trying to process everything.

Lighting cracked across his vision, and he gasped.

Then, out of nowhere, a set of fingers shoved into his mouth.

Katsuki had grown a fifth fucking arm.

Holy shit, holy shit, holy shit.

It was all he could think, the only words that came to mind as those fingers shoved between his teeth, searching and prodding into his mouth.

They pulled out, and Katsuki replaced them with his tongue, kissing Kirishima so hard that he tasted a little blood.

His dick twitched, the pleasure roaring through him making his entire body feel like he was on fire. He cried out, tears rolling down his cheeks as his demon thrust into him again and again and again.

Kirishima’s back snapped up. His legs tingled. Heat inside of him broke, and he came. Semen sprayed out from the tip of his cock, coating Katsuki’s stomach and tentacles.

The demon didn’t stop, though, and the tentacle around the base of Kirishima’s dick only tightened its grip, keeping him hard.

“Sh-shit,” he panted. “Ka-Katsuki, please! Please!”

He didn’t even know what he was begging for, just that he wanted something more. He needed something.

Then, Katsuki’s thrusts slowed to a deep, long grind, and Kirishima cried out again as his demon’s cock rubbed over his prostate. He came again, the semen thinner.

Katsuki moaned and shoved deep into Kirishima’s ass.

Heat filled him.

The redhead gawked up at his demonic lover, panting and gasping as cum filled him and filled him and filled him. There was so much, and Katsuki kept thrusting into it.

Hot, sticky cum dribbled out from his ass, and Katsuki cursed.

His tentacles slipped off of Kirishima’s aching, oversensative dick and shoved inside of him in an attempt to plug him up.

It helped, and Katsuki moaned as his own tentacles stroked him through his orgasm.

Kirishima watched as his lover lifted off his stomach.

And he saw why.

Katsuki hadn’t been kidding about filling him up. His lower stomach had distended and kept growing as more and more cum poured into him.

He moaned, shivering.

Finally, Katsuki sighed. The demon nuzzled Kirishima’s neck before turning them onto their sides. He slid a clawed hand down and rubbed it over the bulge in the redhead’s gut.

“Such a good little slut.”

Kirishima shivered. He couldn’t speak; his throat was raw, and his body ached horribly. Katsuki was still inside him his tentacles still writhing and twitching.

“We’ll go again soon. Get some rest.”

The redhead snuggled up closer to his lover and shut his eyes, relaxing into the other man’s warm embrace.

Again.

He’d be filled again, and again, and again .

And somehow, he didn’t mind.