Reigen wasn’t expecting to feel this way about watching Serizawa exorcise spirits.
It occurs to him that in the time Serizawa’s been working for him, except in cases of extreme duress or high drama, he doesn’t actually spend that much time exorcising garden variety evil spirits—minor hauntings in buildings or caves—nothing major like an Ekubo or Mogami, of course. Though Reigen suspects that at this point, Serizawa probably could snuff Ekubo out like a match if he wanted to. Not that the idea of Ekubo being exorcised particularly appeals to him, but still, the feeling is there.
At first, he suspects it’s the raw power, but then immediately dismisses that idea. Just the thought of being attracted to Serizawa because of his power turns Reigen’s stomach, given past events.
“Hey, Katsuya,” he says as they enter the office one unassuming Monday evening, “great job today.”
Serizawa looks over in surprise, and then he smiles at the praise. “Thanks! I think I’m really getting the hang of it now.”
The fact is that Reigen knows Mob won’t be here forever; he’s getting used to Serizawa now taking on some of the workload since he can control his powers. He also seems to like doing it, and that was the original plan—win-win.
However, one thing Reigen didn’t plan on was getting really embarrassing, unexpected erections as Serizawa puts evil spirits out of commission with that determined, serious look on his face.
But it occurs to Reigen eventually: it’s the confidence. And there’s also something a little bit deeper there that he can only graze the surface of, something about being the adult and telling Mob it’s okay to run away, that it's his job to shoulder the burden alone; but now, suddenly he doesn’t have to.
What is immediately urgent is addressing this little problem he has. Serizawa hasn’t noticed yet, probably because he’s distracted by the fact that he’s actually doing his job without stammering over customers or dropping tea, now that he’s been given an opportunity as Mob becomes a typical teenager, more worried about culture festivals than exorcisms.
Then, there are the exorcisms themselves, and Serizawa’s serious face; and god in those moments Reigen wants Serizawa to bend him over and just fuck him.
The thoughts are crude, but kind of thrilling, new, and probably never going to happen.
Serizawa enjoys sex, and Reigen enjoys sex with Serizawa, but their touches and kisses—while heated and satisfying—are always tender.
So, Reigen lets his imagination run wild. It’s safe that way. He doesn’t have to put in the work of wondering if he’s doing something wrong, or if he’s touching Serizawa in a way that he doesn’t like, or if he doesn’t measure up to past lovers. All things that creep up on him the more they do this, and the longer they’re together.
In his fantasies, Serizawa exorcises a particularly difficult demon. He’s a little sweaty, taxed from the effort, and his aura is clinging to him, dark and mossy green, like heavy smoke; and he looks at Reigen, and grabs him, manhandles him, bends him over, and just takes what he wants.
Reigen comes like this into his own hand many times; it never gets old.
He’s never considered himself a submissive person. Being passive means failure, losing the gamble, letting the mark get one over. But he sort of gets off on trust more than he thought; maybe because it’s so rare, especially when he gives it to someone else.
But Serizawa seems most comfortable playing a role with someone else in charge, and that’s just fine. Reigen wants him to be happy and smile easily and kiss him at the end of the day without hesitation.
Nonetheless, Serizawa was bound to notice eventually that every time they come back from work, Reigen is ready to come in his pants.
“Um,” Serizawa says one night as they’re leaving the office, Reigen locking up after jerking off in the bathroom so his ridiculous erection wasn’t obvious, “Arataka?”
“Hm?” Reigen mutters absently as he fiddles with the lock. He really needs to get that fixed, or have Mob fix it.
“Oh, is the lock still stuck?”
“Yeah,” Reigen complains irritably, jangling the key. “The management still hasn’t fixed it, and I think the cylinder is bent—”
There’s a sudden metallic screech, and then the key turns effortlessly.
Reigen’s eyes widen as he turns to look at Serizawa in surprise, and gets a sheepish expression in response, dark eyes downturned. “Um,” he says, “I can do that now.”
“Saved me a bundle,” he says, grinning at Serizawa as he turns to pull the key out of the lock. “What did you want to ask?”
“Did you, um…” Serizawa’s starting to stammer, and Reigen looks at him in surprise. He hasn’t stammered with Reigen in a while now.
“What?” Reigen cocks his head to the side, unsure of what’s transpiring. Did he do something to piss Serizawa off? Make him uncomfortable?
“Spit it out.” He raises an eyebrow, and reaches out to straighten Serizawa’s shirt collar to bely the sternness of his words, running his thumb gently across Serizawa’s neck before dropping his hand. “Just tell me.”
“Did you masturbate before we left?” he blurts out, his face flushed, like it just took a lot of effort to ask that rather personal, embarrassing question.
Reigen flounders for a moment—as he is wont to do in front of Serizawa, master of Fucking With His Natural Charisma—and he isn’t sure what to say.
“Did you?” Serizawa insists.
Shit. “Maybe?” Reigen wants to die.
“Why do you want to know?” he retorts awkwardly, his voice tense. “Actually, how… why do you think so, anyway?”
Serizawa swallows hard. “I can…” he says slowly, looking anywhere except Reigen’s eyes, “I can sense when you…” he clears his throat, “a little bit. If it’s really...” He looks like he’s going to burst into flames. “Intense.”
“You can sense me come?” Reigen blurts out.
“Only sometimes,” Serizawa says weakly. “Not… well, you don’t have an aura, but it’s an energy. Maybe because… it’s you.”
Reigen doesn’t even have mental energy to unpack that statement right now, but he can address the former issue.
“Yes.” He shrugs. What else is going to say? Thank god Serizawa isn’t a telepath.
“Do I need a reason?”
“Is that why you watch me like that?” Serizawa asks timidly. “When I’m exorcising spirits?”
Reigen wants to melt into the floor.
“I watch you because you work for me!” He laughs awkwardly, and Serizawa just stares at him; god, he’s not even convincing himself. Besides, the employee/employer relationship disintegrated a while ago.
“I don’t think that’s true,” Serizawa replies after a moment, almost wincing as he contradicts Reigen.
Wow, actual insubordination. Impressive. It sort turns Reigen on.
No. No, no, no.
“Okay, fine,” Reigen finally admits, throwing his hands up in exasperation, giving up the charade. “Yeah, it makes me hot, okay? It’s not because of your powers.” Even now, he’s careful to emphasize that, since, as expected, Serizawa’s face immediately takes on a guarded expression before Reigen dispels the insecurity. “You’re confident and good at it… and…” Bend me over the fucking couch already and take me from behind.
Serizawa just stares at him, waits a few beats, and then replies, looking completely and utterly baffled, “Why are you keeping that a secret?”
Reigen’s eye twitches a little, and he laughs nervously. “It’s fine!” he says, shaking his head. “It’s my own problem. It’s not a big deal.”
“Am I not doing things you like?” Serizawa asks bluntly.
“No!” Reigen stammers. “It’s not…”
Serizawa studies him for a moment, and then, something seems to click. “What do you think about?”
God, of all the things that Serizawa is blunt and unselfconscious about, it just has to be the one topic Reigen doesn’t talk about on the regular.
“I think about you,” he says, just in case that part wasn’t clear. But that actually earns an even more puzzled expression.
“So, you masturbate during work hours?”
“Stop saying masturbate,” Reigen groans, trying to derail this painfully embarrassing conversation. “It sounds so clinical.”
Unexpectedly, Reigen finds himself being kissed; it’s soft and gentle. But then Serizawa says low into his ear, “You can talk to me.”
Goddamn it. It’s Reigen’s words echoed right back at him—words that he’s said to Serizawa many times in the past year they’ve been together, and in the past few months they’ve been together.
And maybe Reigen is just tired of jerking off in the bathroom after every exorcism they handle; or hiding things from Serizawa when he knows, deep down, he doesn’t have to. Or maybe there’s some kernel of hope that this ridiculous fantasy could come true, and maybe he trusts Serizawa just enough to admit it.
‘Maybe’ turns into ‘definitely,’ as he blurts out, “I want you to bend me over and fuck me.”
Oh god, he said that out loud.
Serizawa is staring at him with wide eyes, completely still, like an animal waiting to attack or be attacked.
He blinks, inhales sharply. “You mean, take control?”
Reigen clears his throat, attempting to summon a laugh to defuse this situation. He already knows Serizawa’s going to be scared off, and Reigen’s going to lose this entire thing—this perfect, beautiful thing that he doesn’t have to be stressed out about for the first time in his life…
And oh, Serizawa is kissing him, and biting his lip.
The lock clicks again, but there’s no key involved; the door flies open, Reigen is shoved inside the office, and then it slams shut. He finds himself pressed against the wall, and Serizawa actually growls.
“Fuck,” is all Reigen can squeak, before there’s a hand between his legs and Serizawa’s biting at his neck, and a green mossy aura is crackling throughout the entire office and holy shit Serizawa can be dominant.
“If you don’t like this, tell me to stop,” he says, going still for a moment and panting into Reigen’s ear, teeth sharp as he bites at the lobe with just enough pressure to convey he could do some damage, “okay?”
“Okay,” Reigen manages to exhale, and then there’s a hand stroking him through his pants, the lights flicker off, and he can’t do anything but throw his head back and moan, totally and utterly helpless in Serizawa’s grip.
It’s fast and hot, and Reigen can barely keep track of what Serizawa’s doing. His shirt is unbuttoned, and then his belt clicks open and his pants are around his thighs, and Serizawa’s mouthing at his neck as he strokes Reigen’s cock.
“Does that feel good, Arataka?”
“Yes,” Reigen keens, practically crying, registering suddenly that Serizawa is holding all of his weight as he slumps forward. Serizawa sounds a little breathless himself.
“You want me to bend you over still?”
“Bend me over,” Reigen slurs, “fuck…”
And then, as promised, his pants are around his knees, and somehow, Serizawa has moved them to the couch, and Reigen is bent over the back of it with his ass in the air and a hard, firm grip on his hips.
There’s a pause, and then Serizawa’s very sober voice, as he asks, “Do you want to keep going?”
Reigen just gurgles. He has to say yes, has to affirm that yes, he fucking does.
“Yeah,” he slurs out, feeling like someone took away his ability to speak. And that’s an achievement. “Please…”
He’s still wearing his shirt which is hitched up over his back, and his pants are being completely pulled off until his legs are bare, something flies over toward them encased in a green aura, a tube clicks open, and then he feels a slick finger trail down between his ass and oh god that’s happening.
The finger pauses, and Reigen shivers.
“It shouldn’t hurt.”
Reigen inhales deeply, forcing his eyes open, recognizing that tone; this is important. It’s Serizawa’s important voice.
“What?” he exhales.
“I said,” and then that finger is gently moving around his hole, “it shouldn’t hurt. Okay?”
“Uh,” Reigen repeats this statement in his mind, because Serizawa’s important voice is in effect, and he nods dumbly. “Okay.”
At first, as Serizawa pushes a finger into him carefully, it feels… weird more than anything else. It’s sort of arousing, because it’s Serizawa, but it’s also foreign.
“Ah,” he hisses, not sure whether he likes it. All his fantasies, of course, had Serizawa fucking him with his fingers and his dick, and even a tongue when Reigen was feeling really brave; but the reality is different.
But then Serizawa bends over him to nip at his shoulder, and the finger inside him curls, and holy fuck.
He yells. He knows he yells, and if he’s not mistaken, Serizawa hums. Like he knows. Like he knows Reigen was going to love this, like he’s so pleased with himself, and it’s like watching him exorcise spirits, so confident and bright and Katsuya wants him.
“Katsuya,” Reigen exhales, his voice hoarse.
“I like it when you call me that.”
Reigen’s eyes roll back in his head as he gives Serizawa complete control, the finger curled inside of him starting to move slowly in and out, and he instinctively rocks his hips with it.
This is his fantasy come to life: bent over a couch, pants off, at the mercy of Serizawa’s fingers and mouth, practically drooling and totally out of control.
And then, the fingers disappear, there’s a wet sound of stroking, and then he feels something a lot bigger.
“Oh,” is all he gets out before Serizawa gingerly presses forward to let Reigen feel it, the head of his cock rather formidable against Reigen’s ass.
But he grasps Reigen’s hips, and in this moment that is definitely not a simple fantasy where everything slides in perfectly and orgasms are easy to come by, Reigen is grateful for the gentleness of Serizawa’s fingers, making little circles against his hipbones, the kisses against his back, the full blown reality that this is new and not as simple as slip it in, make me come.
Fantasies are a lot easier than anything else, but the real thing is better.
And maybe it’ll get easier; maybe one day Serizawa will be able to flip him over and fuck his brains out without telling him a few times that it shouldn’t hurt.
But Reigen’s okay with how this is going; this is why he’s currently bent over a couch and trusts someone else enough to put a dick in his ass. File under: things he wasn’t prepared for.
“Go ahead,” he breathes, trying to relax.
He gasps as he feels Serizawa’s cock penetrate him slowly and jerks in surprise, not sure whether he wants to call the whole thing off or keep going.
“Are you okay?” Serizawa asks, practically trembling as he stays very still.
“I’m…” Reigen stammers. He takes a deep breath and centers himself; he is okay, and he wants to keep going, even though it’s intimidating. “Yeah.” He trusts Serizawa, though, knowing he’ll stop if Reigen says so, that he doesn’t only listen, but he hears better than any person Reigen’s ever met.
Serizawa pushes in a little more, and now Reigen pushes back gingerly; it feels good. It’s not tender or sweet, but it’s not animalistic fucking either. It’s in the middle, and it’s real, and it’s Serizawa; and he slides all the way in slowly, until Reigen’s breath catches.
“Tell me when I can move,” he murmurs, pressing little aggressive bites down Reigen’s shoulders.
“Just… a minute,” Reigen exhales breathlessly, getting used to the pressure and feeling of it.
“Okay,” he exhales, feeling the grain of the couch upholstery against his hips and cock, leaning forward as he balances his elbows against the cushions, letting Serizawa’s hands hold him still, “fuck me.”
That seems to be enough for Serizawa, as he slowly slides out, and then thrusts back in.
“Fuck,” he hisses, “Arataka…” Then, again, out and in.
The curse and Reigen’s first name out of Serizawa’s mouth make all of this worth it.
Reigen’s thighs tremble as he keeps his legs open for Serizawa, and he’s being fucked in earnest, hard solid thrusts that he’s dreamt about, fantasized about, gotten off to.
His hips are being jerked back, Serizawa’s cock deep inside, and he finally lets go; he yelps, tears in the corners of his eyes, as Serizawa starts to pump his hips.
“Katsuya,” he hears himself groaning, an out of body experience as he’s fucked again and again with that thick cock, “god, that’s…”
This is Serizawa. Nervous Serizawa, who walked into the office late on his first day, confused and unshaven, with his unkempt hair and nervous expression.
This is also Katsuya. Lovely Katsuya, who cares for Reigen more than anyone else ever has.
“Oh, god…” Reigen groans, fumbling for his own cock, but intercepted by Serizawa’s strong hand.
“I’m going to make you come while I’m inside of you.”
Reigen lets out a sharp moan as Serizawa starts to stroke him, thrusting his hips at the same time; and Reigen lets go, losing himself completely in the firm, dominant touches, letting the last of his composure crumble. He hears himself giving short, hoarse cries every time Serizawa pushes forward, using his full strength.
“Come for me,” Serizawa whispers into his ear as he rubs his thumb over the head of Reigen’s cock, his breath stuttering, but his voice is confident and deep.
That’s all it takes, and Reigen comes harder than he ever has in his life; his eyes shut and there are bursts of white and he swears he passes out and wakes up again while Serizawa’s still fucking him.
And even though he’s fucked out and practically comatose, he hears himself beg, come inside of me.
He’s not sure when it happens, though he has a clue when Serizawa’s body goes stiff, and his hips jerk and he lets out a small groan.
Then, Reigen is released. The hands on his hips disappear, Serizawa slips out of him, and he slumps; it’s a little terrifying, because after feeling so filled and wonderfully helpless, he’s never felt more alone in the cool air of the office.
But then, Serizawa is there, and he coaxes Reigen away from the back of the couch to lie down on the cushions where he’s kneeling next to it.
“I can do that for you,” he says gently, “if you liked that.”
“Mm,” is all Reigen can hum, staring up dazedly.
There’s a kiss against the bridge of his nose, and his hand travels up weakly to grasp Serizawa’s arm.
“Is that what you wanted?” Serizawa asks after a few moments.
“I like it sometimes,” Reigen says, trying to form the words properly, “like this.”
“I understand,” he says, smoothing Reigen’s hair back. “You like to be bent over and fucked sometimes.”
“Oh god,” Reigen groans, laughing weakly, “don’t say that, I’ll get hard again.”
Serizawa laughs too, but he sounds distracted. “Is that the first time you’ve ever had sex this way?” he asks.
Reigen’s face heats, but he nods, forcing himself to look Serizawa in the face. “Yeah,” he says simply.
“Are you okay?” Serizawa asks, his face serious now. “Nothing hurts, right?”
“No,” he replies softly, reaching up for Serizawa, knowing he’s being pathetically needy but not caring. “Nothing hurts.”
Serizawa catches his hand and kisses the back of it. “I liked that, too,” he says unexpectedly.
Reigen glances over at him, still trying to catch his breath. “I didn’t know you could, um…” he starts, not wanting to sound condescending, “that you would… want to be…”
“In charge?” Serizawa smiles a little, shaking his head. “Neither did I.”
“But you liked it?”
“Was that… just improvisation?”
“Sort of.” Serizawa replies, rubbing the back of his head as he colors slightly, before moving to push Reigen over enough so that he can haphazardly lie down on the narrow couch with him. Their faces are very close, and he smiles a little uncertainly. “I like when you watch me,” he admits softly.
“Why?” Reigen asks softly, adjusting to fit his body against Serizawa’s more easily. It’s become familiar very quickly; almost disconcertingly so. Being naked and close feels so comfortable Reigen isn’t even sure what to make of it, since most of what he calls his ‘nocturnal activities’ haven’t exactly been satisfying or fondly recalled.
“It makes me feel confident.”
“Me staring at you like a horny teenager makes you feel confident?” Reigen asks in disbelief, and then he can’t help but widen his eyes as Serizawa laughs.
“I guess so.” He smiles, but when his eyes land on Reigen, they’re soft. “You’ve always made me feel confident because you were never afraid of me.”
Reigen looks away, clearing his throat and pushing his face against Serizawa’s shoulder, hoping the heat in his cheeks isn’t obvious. “Right,” he mumbles, “well, now that I know what you’re capable of, maybe I should be afraid. Or at least my ass should be.”
He’s relieved when that earns a rumble of laughter out of Serizawa, and then an affectionate sweep of his hand through Reigen’s hair, before he pulls back.
Their eyes meet, and he smiles, his expression warm. “There are lots of things I might be capable of,” he says quietly, his face turning a bit more serious. “If you want to try, you just need to ask.”
Reigen nods, feeling a slight soreness from where Serizawa had fucked him, but in some unexpected way, he likes it. It’s a reminder, and it makes him feel more relaxed than he has in years.
“I like it when you call me Arataka,” he says abruptly. “I liked it from the first time you said it.”
“I like it, too,” Serizawa replies softly.
They just lie there together, until Reigen murmurs sleepily, “Maybe I should put my pants back on so we can actually leave work. Do you still want to come over?”
Serizawa smiles a little, casting his gaze down Reigen’s body appreciatively, a slight blush in his cheeks as he nods. “I’d like to.”
“I’d like to try something really extreme,” Reigen declares, slowly sitting up with a grunt, gingerly testing his ability to move.
“What’s that?” Serizawa asks, sounding baffled.
“Cooking,” he exclaims, fumbling around on the floor for his underwear and pants.
“That’s way too extreme for me, Arataka,” Serizawa says, his voice warm and playful, so different from when he’s nervous or unsure of himself.
“Just try it,” Reigen teases back, “you might like it.”
There’s a strong pair of arms that pull him back down, a kiss against his hair, and Serizawa makes a contented noise.
“I can’t wait.”