A/N: this took waaay longer to write than anticipated cause I had to rewrite it, like, 8 times because they all felt like trash. this one does too but it hurt way less to look at than the others. man, I'm getting rusty. anyway, I hope that you enjoy! this should go without saying but um...SMUT WARNING ft. kinks and sexual vulgarity. oh, and this isn't gonna be a poly fic but it will spark quite the development in Shouto and Katsuki's ✨friendship✨

Izuku can't believe that he said yes. 

Or, rather, he can't believe how incredibly easy it was for Shouto to persuade him into saying yes. Mutely, Izuku happens to think that Eijirou's utter lack of a backbone had been rather laughable. 

The half-and-half boy had done little more than float his way over to the bar with that sly little grin on his face, trailing those pretty little pink-painted fingers up Eijirou's chest as he'd leaned forward onto the tips of his toes to whisper something undoubtedly devious into the redhead's ear and just like that, Eijirou had completely melted like putty right into Shouto's hands.

Izuku minutely thinks to remind himself to bust Eijirou's balls about it some other time. As fun as it would be to embarrass him right now---to call him out on his shit? Izuku is much more enamored with the two gorgeous babes that are making out in his bed than he is with the idea of ruining the mood just to comment on how spineless his friend had actually turned out to be. 

Instead of confining himself to a corner for the night like Eijirou seems to have in mind, Izuku decides that he'd much prefer a front row seat to such a lovely show so he takes one at the foot of the bed. 

To see their lean, naked, sweat-slicked bodies rutting up against one another is so much better from this angle---they're so different but equally as gorgeous. Shouto's frame isn't as small as Katsuki's, taller and quite a bit more muscular in comparison to Katsuki's much smaller and softer form. Where Katsuki's body has developed curves and a sort of gentle roundness, Shouto's is much tighter---much more lean and toned. Even Shouto's cock is bigger, longer and thicker than Katsuki's own, hanging heavy against Katsuki's pale and milky thigh. 

Everything about them is such a beautiful contrast. 

"Such pretty boys; so beautiful when you kiss each other like that. You're so sweet to one another." Izuku praises them both, encouraging them not to be so shy with one another just because he and Eijirou are watching. He gathers that Eijirou will most likely be rather absent in their little playdate tonight, completely stuck to the chair that he's sitting in with that absolutely gobsmacked expression plastered to his face. His cock is hard and straining against his slacks, buttons undone and tie hanging haphazardly around his neck. Figures that he'd be so floored; he's practically drooling. 

In comparison? Eijirou is rather vanilla. He lacks most of the experience that Izuku has with things like this. 

But Izuku doesn't mind being the only one to coach their lovely boys through this little scene tonight; he reckons that Eijirou wouldn't even know how to go about doing so anyway. 

Best that he just sit back and watch. 

"Shy?" Shouto parrots with an amused hum. "I'm just trying to make sure that my baby Kat can feel just how much I love him. Mark up that pretty skin. Play with those pretty tits. He just feels so good on my tongue, you know?" He murmurs against Katsuki's collarbone as his tongue laves across a rather large hickey that he's left in his wake. His hands grope and squeeze and pull at Katsuki's backside, fingers gently digging into the soft skin there. 

Katsuki can do little more than cling to Shouto, hips twitching against the taller boy's thigh as Shouto's teeth scrape against the sensitive skin of his neck. 

Izuku feels the corners of his mouth curl into a smile. "In other words, you want to be greedy while you've got the chance. I can tell that you've been wanting to do this for quite some time and I don't blame you at all; Kacchan is absolutely perfect." He says, calloused fingers reaching out to pet Katsuki's unruly mane. He plans to keep his boundaries tonight and let Shouto do as he pleases. He doesn't need to be on the giving or receiving end of any of this in order to have a good time. "You've been such good boys tonight---playing so nicely together. You can have Kacchan however you'd like to have him tonight, baby. It's the least that I can do to treat you both." 

"Yeah?" 

"Of course." 

"Hm. Are you sure that's not just an excuse for you to perv out over two hot little twinks?" 

"And if it is?" Izuku challenges smugly, taking a moment to reach into the bedside table to get lube and condoms for them. He's unsure of just how far Shouto is going to take this, but he at least wants for them both to be safe and comfortable. Katsuki's already had so many bad experiences with sex from his past relationship and it's taken Izuku quite a while to get him used to having sex that he actually likes. He doesn't want a poorly planned scene to ruin that. 

Shouto huffs a laugh. "No objections from me, honey. But if you're planning to fuck me, you're gonna have to wait your turn. Kat comes first. If you're still hard by the time that I'm done, though, then I've got two holes that you can use and I can take a fat dick with no problem." He gives Izuku a very apparent once over, eyes lingering over the tent in his pants. "And I can tell that you're a pretty big boy." 

Izuku's smile broadens, hand reaching out to rub at the small of Shouto's back appreciatively. "You're such a sweet boy; I don't know why Eijirou was complaining about you being a brat." He chuckles, not at all missing the way that Shouto's eye twitches at being referred to as a brat. It occurs to him that he may have just gotten Eijirou into some trouble. 

Whoops. 

"As sweet as you are, baby, and as cute as your little pussy is, you don't have to worry about me tonight. I'm happy just watching the two of you. Sleeping with either of you wasn't in my conditions for this. I'm not expecting anything in return. I just want to see my Kacchan happy." And completely fucked out by his hot as fuck best friend, but he doesn't feel it necessary to tack on such an afterthought. Besides, he's not sure just how much Eijirou has agreed to tonight but he doesn't want to cross any boundaries with him either. 

Although, if it were Eijirou in his shoes, Izuku doesn't think he'd mind much. He and Shouto are the only exceptions that he's willing to make to this monogamy of his. 

Shouto claps his palm against Katsuki's ass with a giggle, drinking in the sweet sound of Katsuki's ragged and shaky moans. "What do you think, Kats? You wanna lemme have my way with you?" He teases, free hand sliding up the lean expanse of Katsuki's front to gently grab him by the throat---he's demanding his full attention. 

Katsuki's teeth sink into his lip with a hiss, staring up at Shouto through long and fluffy lashes with a flirtatious gaze. Lithe fingers reach to wrap around Shouto's cock in languid strokes, goading him as the taller boy's grip tightens around his neck. 

Kiss-bitten lips curl into a dazed and lovestruck smile. 

"Wanna be a slut for you."

It's so soft and gentle---the way that he damn near whispers it into the air between them. Like a declaration of love and not just lustful babbling. It sends a shiver running right down the length of Shouto's spine and Izuku, completely enamored by the two of them, can see the very moment that Shouto begins to melt. It's funny, in a way, to see just how much power Katsuki has over him. 

"You wanna be my slut, baby?" 

"Yeah~" 

"Good slut boys like to deepthroat a good dick to get it sloppy wet for their sweet little cunts. Can you do that for me, baby?" 

Katsuki's frantic, eager little nod makes Izuku swoon. He's so fucking eager to please---desperate for Shouto's attention in a way that he's never been for Izuku. It's so easy to tell that he's a lot more used to his subspace when Shouto is the one domming him---easing him into it and fulfilling all of his needs without ever pushing Katsuki too far.

He wonders just how far they've gone before. Izuku's almost inclined to think that Shouto is a much better dom than Izuku himself is---much more experienced as he seems to do so with effortless ease. 

He would be jealous if he didn't find it so endearing.

Maybe he should ask him for a few pointers when this was all done.  

#

Eijirou's mind is absolutely reeling. 

He's aware that he must look like a fucking idiot, sitting there with his dick in his hand and drooling over himself like a slobbery mutt but fuck he can't think of a more appropriate reaction to watching Shouto use Katsuki's mouth like his own personal fuckhole. He's completely dominating him, hands tangled into flaxen strands to force him up and down his shaft until Katsuki's coughing and gagging around him. He's manhandled the smaller boy onto his knees and demanded that he keep his arms folded behind his back. 

It's all that Katsuki can do but brace himself and take it but if the look of unbridled joy on his face is of any indication at all then Eijirou is willing to bet that he prefers it that way. 

Frankly? Watching Shouto be such a top was enough to make him nearly lose his mind.

And God, is Katsuki absolutely fucking stunning. 

Up until now, Eijirou would never have believed that someone other than Shouto could look so goddamn ethereal with a cock in their mouth---swollen lips wrapped tightly around it with tears streaming down those pretty, ruddy cheeks every time the head of Shouto's cock rams into the back of his throat. He's adamant about keeping himself restrained---about making sure that he's obeying all of Shouto's orders right to the letter. 

There's nothing innocent about it at all but somehow Eijirou still finds it incredibly sweet. 

And yet, here he is---so incredibly close to cumming that it's embarrassing. Izuku hasn't touched himself even once, coaching and coaxing their two little lovebirds through their lovemaking with an expression that Eijirou could only equate to a proud father. 

He squeezes the base of his cock in an attempt to get himself to suppress the urge to splatter his friends' bedroom floor in his seed. 

"Katsuki---fuck, baby. Gimme that fuckin' throat. God, you're such a sweet little Kitty; you just sit there like a dumb fuckin' slut and let me choke you on my dick until your throat's sore. But I'm almost there, baby. Just keep givin' it to me and I'm gonna cum---you want that?" Shouto's rambling, mostly to himself as Katsuki's mouth is still full but the little squeal of affirmation that he does is incredibly cute. 

The sound of spit and drool being fucked out of him echoes off of the walls in the most lewd and obscene way, only serving to spur Eijirou on with those weak and halfway abandoned little thrusts that he does against his own palm---fuck, this is hot. 

"Good boy, Kacchan, there's my good boy~" Izuku coos from behind Katsuki, seated on the floor behind with his chest flush against his back. Eijirou had first assumed that he was holding Katsuki's arms behind his back but he can see now that he's just massaging Katsuki's inevitably sore thighs with his hands. He 's cheering him on, whispering praises into his ear even as he encourages Shouto to chase his orgasm. The half-and-half boy's crescendoing cries of 'give it to me, fuckin' give it to me, baby' tell him that he's not far from it. 

"There we go, Shocchan. Don't take it out, baby, cum right down his throat. He deserves a treat for being such a good boy, don't you think?" 

"Mmmmhm, fuck yeah! Fuckin' mouth is so good---can't wait until I finally get inside of you. Wanna fuck you so bad, Katsuki, wanna make you cum---"

Shouto's hips stutter with a sharp gasp, legs buckling as he holds Katsuki down on his cock until his balls tap against his chin. Eijirou can see Katsuki swallowing around Shouto until those mismatched eyes go rolling back and Izuku gently separates them, watching Shouto sink down onto his knees to catch his breath. 

"That's my Kacchan~! You did so well, baby boy, daddy is so proud of you." Izuku croons, arms wrapped around Katsuki's middle as the blonde's body slumps forward in his lap. He seems to be completely out of it at first but the moment his head lands on Shouto's shoulder, he's whining and pawing at him with shaking hands. Shouto is easily able to take hold of him, fingers carding through his messy hair as he whispers reassurances into his ear. It seems to calm him down rather quickly, Shouto's free hand rubbing soothing circles into his back. 

"D-Did I...did I-I do good for you?" 

"Oh, baby, you were perfect." Shouto corrects him, pressing his lips against Katsuki's sweaty temple as Izuku disappears into the adjoining bathroom to presumably go and grab a wet washcloth to clean the filth from his face. He returns with it a moment later and allows Shouto to do so without interfering. Shouto appreciates that he doesn't feel the need to insert himself into moments like these---moments that were meant for him and Katsuki alone. 

He's mutely aware of Katsuki's own need poking him against his leg.

"Tell me what you want now, baby. Whatever you want, I'll do for you." He whispers, wiping the rest of the sloppy mess clean from Katsuki's face and chest before he hands the rag to Izuku. He disappears once more to go and dispose of it but, again, he doesn't seem to be interested in interfering or offering an opinion. 

Good. This isn't about him. 

#

Shouto often wonders what life would have been like if he and Katsuki had fallen in love with each other instead of hopeless losers like Yoarashi and Yo Shindou. How much happier would their lives have been? How much heartache would they have avoided? Would they have been strong enough to last? They were both much too afraid to try and find out. 

But Shouto---the selfish bitch---couldn't leave well enough alone. 

It was innocent enough---the way that things between them had started. Sneaking kisses underneath the blankets after a long night of drinking wasn't supposed to be something that he'd make a habit out of but after he'd gotten away with it once or twice, it had become rather addicting. 

Sneaky little kisses became make-out sessions. 

Make-out sessions often turned into Shouto fingering Katsuki in his bed when his days were particularly rough on him. 

Messing around with Katsuki had become somewhat of a coping mechanism for Shouto---though he likes to think that Katsuki was rather fond of it as well. On those nights, he thought more often about what things would be like if Katsuki had been his instead. Wishful thinking, he'd always say. And instead of talking about it, they'd just keep messing around. 

But they've never gotten this far before. 

They've never gone all the way. 

Not until now. 

It feels so surreal, having Katsuki nearly folded in half beneath him simply to take the brunt of Shouto's love and take the entirety of his cock in one quick push. He shouldn't be as surprised as he is that Katsuki takes him so easily considering the fact that he's fucking someone like Midoriya—Midoriya, who just so happens to be walking around hung like a fucking horse. Katsuki must be well-adjusted to such a stretch and even still, with Shouto's cock pressed firmly against his prostate, Katsuki's insides are incredibly tight.  

"O-Oh my God, Sho---" he gasps, toes curling as Shouto rubs the head of his cock up against his sweet spot. His nails dig into the skin of Shouto's arms, thighs squeezing around Shouto's middle. "Please, please, please just move---yes !" 

Shouto obliges him without any teasing or fanfare, having lost the capacity for his usually smug commentary as he's overcome with an unbridled and hungry lust. He's not being very gentle, he realizes---the headboard is slamming against the wall rather aggressively and Katsuki's cries are doing a phenomenal job at egging him on.

"Oh my God---oh, fuckfuckfuckfuckfuck !" He screams, squealing when Shouto's free hand reaches up to wrap around his neck and pin him to the bed. 

"Katsuki, my baby. I love you so fucking much, baby, so much. Oh, no, no, keep those pretty thighs spread for me, Kitty Kat---there we go. There we go, honey, doesn't that feel good? Hm?" 

Katsuki's eyes roll back into his head, knees clamping down around Shouto's waist as the assault on his prostate becomes just a bit short of too much. He's begging, tears welling up into his eyes as the hand around his throat squeezes even tighter and brings Katsuki down onto his cock to meet every upward thrust. 

"Kacchan likes to be treated like a five dollar whore, then? He looks so happy with you choking him like that---look how cute my baby is." Izuku muses, lying next to Katsuki as he jerks himself with lazy strokes. He seems to be focused on the face that Katsuki's making---damn near cross-eyed with pleasure with that ditzy little smile on his face as Shouto squeezes him tighter. He's drooling all over himself again, clawing at Shouto's back as his legs hook around his waist to pull him tighter. 

"Yeah, he fucking loves it. Loves it when you fuck him like you hate him---don't you baby?" Shouto chuckles, driving his point home with another brutal thrust against his prostate.

Mindlessly, Katsuki agrees. 

"Who's a good fuckin' slut?" 

"M-Me---I-I-I'm a g-good slut~" 

"That's right, baby. Whose slut are you?" 

"Yours---I-I'm yours!"

"Fucking right, my sweet baby. Mmm, you'll have to thank daddy for letting us play, you know." 

"Thank you so much, daddy~" Katsuki's words begin to slur and it becomes increasingly difficult for Shouto to keep his own orgasm at bay. He doesn't want to cum before Katsuki does again but at this rate, he's not going to last very long. 

He reaches down to wrap his fingers around Katsuki's dick and squeezing tight, powerless to do little more than stare in complete awe as Katsuki's body goes taught and he arches up from the bed. His orgasm leaves him with violent convulsions, spilling all over Shouto's hand with a choked squeal. 

Shouto's body curls over Katsuki's own as his orgasm crashes into him like a freight train but he doesn't stop working Katsuki until the body beneath him goes limp from the strain of delicious overstimulation. 

"Fucking fuck---baby. Holy shit…" 

He's sprawled over Katsuki's body, cock still pulsing inside of Katsuki's sticky, wet opening as their bodies scream for a reprieve. 

He feels a soothing hand at his back upon trying to sit upright again. 

"Don't worry, sweetheart, it's just me. Don't worry about cleaning up, okay? I've got you both; just rest. You've over-exerted yourself." 

Oh. 

Over-exerted? 

Admittedly, his limbs do feel completely useless but Shouto's unsure if he'd consider himself past his limit. 

Although, that could just be his stubborn pride talking. 

Who is he to deny Izuku's help?

"Are they okay? I can get him if you need me to; I've been pretty useless this entire time." He hears Eijirou's sheepish voice and, frankly, he'd forgotten that Eijirou was even there to begin with. He'd been a ghost for a majority of the night, after all. 

At least he's trying to be helpful. 

"Sure. We need to get them comfortable and clean---make sure they're alright mentally as well as physically. Separating them tonight probably isn't the best idea. We should let them have the bed, but I need to put clean sheets on as they've made quite a mess. Would you rather start the bath or change the sheets?" 

Eijirou pauses. 

"Ah...I guess I'll change the sheets? I'm not the best at the whole aftercare thing. I don't want fuck this up---"

"Hey, that's okay. You know where they are?" 

"Yeah."

"Alright. In that case, I've got the two of them." 

Shouto feels himself being lifted up from the bed and immediately hears Katsuki's incoherent whining the moment Shouto is plucked from him. It only lasts a moment, Izuku moving to grab Katsuki at the same time to make sure that they're kept together until Katsuki comes to again.  

Tonight, Shouto has finally gone all of the way with Katsuki. He can't quite say how he feels tonight; his judgement is clouded by the fluttering feeling in his chest. 

He wonders how Katsuki will feel about him come morning.