Chapter Text
Alpha Bakugou working out at a 24hr alpha only gym at 1 o'clock in the morning so no one bothers him. He doesn't worry about wearing scent blockers because he's the only one there. Even if another alpha shows up he's ready for a fight if they have the balls to mess with him.
He's drenched in sweat from his hardcore work out, forming large puddles where ever he goes. Bakugou looks like he just got out of the shower. The gym smells like pure him and he loves it, surely if another alpha comes by they'll know to stay away.
So when a shitty haired alpha shows up asking if Bakugou can be his spotter he's caught so off guard that he agrees instead of telling the other alpha to get lost. Friendly interactions in an alpha only gym are rare, asking for a spotter to do bench press is unheard of. No alpha wants another alpha's sweaty ball in their face. Apparently this alpha did...
He laid down on the bench, spikey red hair brushing against Bakugou's legs as he stood over his shoulders and glared down at the other alpha.
"I'm Kirishima by the way, thanks for helping a bro out!" Kirishima grinned under him.
"Bakugou" he grunted trying to tone down his scent, but he had never been good at masking it. Kirishima, on the other hand, was wearing multiple scent blockers so Bakugou couldn't tell what he was thinking behind that dangerous shark tooth smile.
Bakugou put his hands on the bar to help Kirishima get started, but the other alpha didn't budge. He looked down and caught the other alpha staring between his legs. Bakugou snarled and Kirishima's eyes shot up.
"The fuck are you doing shitty hair" Bakugou growled threateningly.
"Heh, s-sorry you're just sweating like /a lot/ and you're not wearing scent blockers so..."
"So what? It's a fucking gym of course I'm gonna sweat. Idiot."
Kirishima laughed uncomfortably and nodded trying to turn his attention back to the task at hand. Kirishima did his set quickly and then practically dropped the bar on the last rep. Bakugou yelped as he was jerked by the sudden weight. He leaned forwards and bent his knees to keep himself from dropping the bar, wincing when he felt his junk land right on Kirishima's face before he quickly stood up and put the bar on the rack.
"What the /fuck/ shitty hair, you can't just drop it like that!"
Bakugou looked down and inhaled sharply. Kirishima looked like he was in a daze, eyes half lidded, face flushed, and mouth slightly open, his face was shiny from a mixture of Bakugou's sweat and his own.
Kirishima let go of the bar and reached for Bakugou's thighs, his claws digging into his flesh as the alpha pulled him closer.
"O-oi what the hell do you think you're doing?"
Kirishima let out a low, rumbling growl and craned his head back, licking Bakugou's balls through his sweat soaked compression shorts. Bakugou hissed, grabbing the bar so tightly his claws cut into his palms. Bakugou couldn't stop himself from rutting against Kirishima's tongue, the other alpha moaned loudly and tried to pull him closer.
"F-fuck" Bakugou groaned, his eyes screwing shut "W-what are you doing?"
"/Alpha/" Kirishima snarled, his sharp teeth scraping against the thin material of his shorts "You smell so good"
Kirishima hands slid up Bakugou's thighs and hooked around his waistband. Bakugou growled but didn't stop him from peeling his shorts from his body.
"Need more" Kirishima moaned watching hungrily as Bakugou's half hard cock sprung free and his musk filled the air.
Bakugou looked just in time to see Kirishima put his tongue on his bare leg to catch a bead of sweat that trickling down and lick all the way up to his nuts. Bakugou moaned, doubling over to rest his head on the bar while Kirishima lapped at his balls.
"I can smell your arousal" Kirishima purred, running his fingers up under Bakugou's loose tank top "you're not even trying to hide it from me. /good Alpha/"
Bakugou was trying to hide it, he just wasn't doing a good job. But he whined at the praise anyway, groaning as Kirishima sucked one of his balls onto his mouth and hummed around it. Kirishima released him with a loud wet pop, his hands wrapping around Bakugou's thin waist. Bakugou didn't realize just how big Kirishima was until he felt the other alpha's thumbs touch.
"So small..."
"Fuck you, knot brain. If you're gonna suck my dick just do it." Bakugou hissed, pushing the head of his cock into Kirishima's mouth "You won't make fun of me when I knot your mouth. Stupid alpha"
Kirishima moaned loudly, hips rutting against the air as he pulled Bakugou deeper into his mouth, tongue swirling around the head and sucking greedily.
"Of course /you'd/ like that. Fucking perv"
Bakugou pulled his hips back and snapped them forwards roughly, moaning as Kirishima gagged on his thick cock. Wet slurping sounds filled the air as Kirishima tried to keep up with Bakugou's hips, balls slapping against his forehead. Drool spilling out of his mouth as Bakugou abused the back of Kirishima's throat, trying to force himself inside.
"//Swallow//" Bakugou commanded and Kirishima obeyed, his throat bulging around Bakugou's length as it slid in until his knot hit his lips.
Kirishima's claws dug into Bakugou's skin when his air was cut off, but he didn't pull away.
Bakugou grabbed Kirishima's neck with one hand to hold him stead as he began roughly fucking his throat, feeling his cock moving inside under his thumb.
"Good alpha, fucking take it" Bakugou growled feeling Kirishima's throat tighten around him "I'm going to make you my fucking bitch"
Bakugous could feel his orgasm coming. The urge to force his knot into Kirishima's mouth was almost too much to resist. So instead he grabbed his knot with his free hand and squeezed tightly, the pressure sending him over the edge.
Bakugou came with a shout, shooting ropes of cum down Kirishima's throat, choking him as he struggled to drink everything that Bakugou gave him. It leaked out of the corners of his mouth and into the floor.
Bakugou pulled out slowly. Just before his head was out Kirishima shoved Bakugou back, coughing and gasping for air. He was grinning but Bakugou still couldn't tell what the alpha was thinking, those scent patches were driving him insane.
Without think Bakugou lunged forward and ripped one off.
"Hey!"
Kirishima's scent immediately overwhelmed him and Bakugou staggered back. It was thick and strong and heavy with arousal and... And something more...
"Alpha prime" Bakugou breathed, he threw his hand over his mouth and nose, trying not to breathe because there was something else there.
//Rut//
"You shouldn't have done that" Kirishima growled but he made no move to cover his scent.
"You shouldn't be in public, what are you crazy?" Bakugou tried to sound angry but the smell of a rutting alpha prime was messing with his head.
Kirishima took a step towards him. Bakugou stated to take a shaky step back.
"//Stay//"
Bakugou's whole body locked up, his body felt like it was being crushed under the command. He watched nervously as Kirishima reached up and tore off the other scent blocker.
"W-what are you doing?" Bakugou gaspedKirishima's scent was so strong he could taste it in his mouth
/rut rut rut/
"Stop scenting! You're gonna make me-"
Bakugou stopped when Kirishima touched him, the alpha prime's claws brushing against his scent gland sending electricity up and down his body. Kirishima grabbed Bakugou's jaw with his huge hand, turning his head to the side to expose his neck. Bakugou snapped his teeth and growled, pushing back against Kirishima.
"No, bad alpha" Kirishima rumbled "//submit//"
Bakugou hissed, his body trembling as he struggled against the command as Kirishima pumped more of his scent into the enclosed space. Bakugou felt dizzy, he could feel his temperature rising and his heart pounding. His gums ached to sink into flesh.
Kirishima licked a stripe up Bakugou's exposed neck and nipped his ear.
"//submit//" Kirishima repeated, his lips brushing against Bakugou's jaw.
Bakugou's head slumped to the side.
"Good alpha"Kirishima leaned in and brushed his fangs over Bakugou's scent gland.
Bakugou's roared pushing Kirishima back enough so he could sink his teeth into the side of the alpha prime's face. Kirishima's claws pierced into Bakugou's triceps and that tumbled to the floor biting and clawing at each other as their feral growls filled the room.
Bakugou was in pre rut already, his thread of control hanging on by a thread. He found himself on top for a moment and straddled Kirishima's hips, holding his wrists over his head.
"My rut... Why?" Bakugou's managed to hiss before his mind completely slipped away.
"Just returning the favor" Kirishima smirked, rolling his hips up, his clothed erection sliding between Bakugou's cheeks.
Bakugou growled viciously ready to bite again when Kirishima flipped them over, slamming Bakugou's face down in a puddle of his own sweat. The alpha prime grabbed Bakugou's hips roughly, his claws cutting deep as he pulled his ass into the air.
"//Present//" Kirishima commanded
Bakugou whimpered his inner alpha fighting between the desire to take and the need to follow a prime's command. He clawed at Kirishima's hands, but he didn't know if he was pushing him away or pulling him closer
"Alpha!" Bakugou cried out, his voice coming out as a needy whine.
Kirishima scraped his teeth against Bakugou's inner thigh then bit into his firm ass. Bakugou screamed.
"Noisy for me" Kirishima slurred, licking the blood away before blowing a stream of cool air against Bakugou's hole.
Bakugou's pushed back towards his face but Kirishima kept him still in his steel grip.
"You want me?"
Bakugou's growled
"//say it//"
"I want you!"
Kirishima hummed and pressed his tongue into the tight ring of muscle. Bakugou's clamped down against the foreign sensation, but Kirishima moaned and pressed in deeper. Kirishima went to work opening Bakugou up with his tongue, holding the squirming alpha in place with one hand as he tried to focus enough through the haze of his rut to retract his claws on the other. When Kirishima deemed Bakugou ready he roughly shoved two fingers inside of him down to the knuckle. Bakugou's growls turned into a loud cries of pleasure as Kirishima pumped his fingers in and out, forcing in a third finger.
Bakugou's alpha was going wild, he enjoyed the intense pleasure even the burn had his eyes rolling back and his cock leaking, but he wanted to /take/ not be /taken/. The need to claim make his gums ache and his skin crawl.
Then Kirishima curled his fingers and Bakugou's alpha went quiet as he screamed.
"Alpha!"
Kirishima added a forth finger and hit that spot again and again until Bakugou was a drooling whimpering mess, his ass trying to milk Kirishima's fingers as he pulled out. Bakugou looked over his shoulder and watched Kirishima shred his sweats in his attempt to remove them.
/strong/ he alpha noted with approval.
Then Kirishima took out his cock and Bakugou gulped. It was /huge/, easily the size of Bakugou's forearm, flushed and leaking pre. Kirishima stroked it and Bakugou watched it twitch in his giant hand that couldn't even close around it.The alpha prime caught him staring and smirked as he lined up with Bakugou's stretched hole.
"//relax//"
Bakugou's body complied, his muscles going slack and his eyes half closed. He felt the head push against him and pop inside. Bakugou's eyes rolled back and his mouth opened in a silent scream as Kirishima grabbed his hips again. The alpha prime moaned as he pulled Bakugou back onto his cock.
Bakugou felt impossibly full, like there was no way he could take more, but Kirishima kept sinking into his right heat until his barely formed knot kissed his entrance. Kirishima grabbed Bakugou's arms and lifted him up until his back was pressed against Kirishima's chest.
"Good. Good alpha" he praised as Bakugou struggled to catch his breath. "You're taking my cock so well. So good. Perfect mate."
Bakugou whined, choking on a cry when Kirishima rocked his hips. Kirishima kissing and licking his neck, Bakugou's alpha hissing while Bakugou moaned and bared his neck for the alpha prime. He felt Kirishima's cock twitch at the submissive display.
"So good" Kirishima repeated his thrusts gaining more force "look at how well you're taking my cock. Gonna knot you so good"
Bakugou moaned, opening the eyes he didn't realize is had closed and gasped. When Kirishima pushed all the way inside his cock caused Bakugou's stomach to bulge out slightly. Kirishima rolled his hips and Bakugou watched the bump in his stomach move.
"So big, alpha"
Bakugou felt Kirishima knot grind against his hole. The alpha prime wasn't even all the way inside yet. Kirishima tightened his grip on Bakugou's arms, pulling them back to use leverage as the alpha prime set a brutal pace. The room filled with the sounds of wet slapping skin and the smell of sex and pleasure. Each rough thrust would force a little more of Kirishima's massive knot inside.
"M gonna knot you" Kirishima moaned, his teeth teasing dangerously around Bakugou's scent gland "knot you, breed you, make you /mine/"
Bakugou's alpha roared at Kirishima's words. It's should be the other way around! Bakugou's snarled, struggling to free himself from Kirishima's grip.
He tore his sweaty wrists out of the alpha prime's grasp and they fought for dominance again. Kirishima was build like a tank and strong but Bakugou was faster. Even through the haze of his rut Bakugou was still a more strategic fighter. He forced Kirishima back until he tripped over a barbell Bakugou had neglected to put away and then he lunged.
Kirishima put his arm up to push Bakugou off and Bakugou's sunk his teeth deep into his forearm. He held Kirishima down with one hand firmly on his throat, the other grabbed Kirishima's thick cock and lined it back up with his entrance.
"I take /you/" Bakugou hissed, his words muffled by Kirishima's arm "make you mine"
Kirishima's wheezed, tearing his arm out of Bakugou's mouth to claw at the hand obstructing his airway and Bakugou's sunk down. He whimpered, drool and sweat dripping off him as he was once again stuff with alpha cock, the sensation causing him to clasp right around Kirishima's throat. Kirishima's eyes rolled back as his face turned red, unable to get the leverage he needed to push Bakugou off.
"//submit//" Bakugou moaned, his face twisted into a crazed smirk as he stared into the alpha prime's eyes. Kirishima bared his fangs but let his head fall to the side and Bakugou loosen his hold so Kirishima could breathe.
Bakugou's alpha preened, victorious, and he lifted himself up before slamming back down, bouncing up and down on Kirishima's length. Bakugou felt amazing, his knot rapidly growing each time Kirishima slammed against his prostate. The alpha prime below him letting out a mixture of whimpers, moans, and snarls. Anytime Kirishima made a threatening noise Bakugou would squeeze his hand and choke him. Kirishima would show his neck and Bakugou would let go.
"K-knot" Kirishima whined, rolling his hips up to meet Bakugou's.
Bakugou slammed down harder, grinding down against Kirishima's fully formed knot.
"Too big" Bakugou growled "won't fit"
"Knotknotknot" Kirishima chanted grabbing Bakugou's waist and forcing him down harder.
Bakugou put his hands on Kirishima's pecs to support himself, gasping and moaning as his orgasm approached.
"Won't fit" Bakugou groaned again, digging his claws into Kirishima's muscles.
"//make it fit//" Kirishima growled
Bakugou's whined but felt himself relax immediately, Kirishima taking advantage of the effect his command had to flip them over. Bakugou hit the ground hard, stars flashing behind his eyelids as his breath left in a rush leaving him gasping for air.
Kirishima hooked his arms around Bakugou's legs and brought his knees to his head, bending the alpha in half underneath him. With one last forceful thrust Kirishima's knot popped inside, locking them together.
Bakugou screamed as he came, shooting ropesand of cum onto his chest, neck and face. The sensation of Bakugou's ass milking his knot sent Kirishima over the edge, he ground his knot deeper as he came, painting Bakugou's insides white.
The alpha prime leaned in and sunk his teeth deep into Bakugou's shoulder barely missing the alpha's scent gland. Kirishima collapsed, cradling Bakugou in his arms as be gently licked the blood from his fresh wound.