For the Sake of Study, a genshin impact fanfic

For research, said Alhaithem. Kaveh should know better by now that with this man, nothing is as it seems.

He'd broached the topic casually, leaning against Kaveh's drafting table with a cup of coffee in his hands. "Prostate milking," he'd continued.

Kaveh's graphite slips and he fucks up his design. Irritated, he glares at Alhaitham, pink with rage and arousal. He's a man. Sue him. "Your nonsense has ruined my work," he snaps, grabbing a rubber eraser to smooth away his fuck-up.

Alhaitham just sips his coffee, as if he didn't just ask Kaveh to fingerfuck him into overstimulation. Kaveh can feel his gaze on the back of his neck. Heated. Carefully placed. Kaveh sucks in a breath and turns back to him.

"You're insufferable, aren't you?"

"I'm asking for your help with work."

Kaveh's gaze narrows. "This isn't for work, it's to satisfy whatever debased curiosity currently has you in a chokehold. I'm sure there are plenty of men who'd happily indulge in your fantasy, but—"

"I am asking you." Alhaitham's voice is quiet but firm.

It's not as though it's the first time they've fucked—Kaveh's lost count of how many times they've given in to each other. He spends more time in Alhaitham's bed than in his own. He has a pillow permanently situated on the left because that's his preferred side, and when he told Alhaitham that, Alhaitham just laughed and kissed his brow.

Still. This implies a level of trust that… Kaveh is not sure he's willing to entertain. He wants to, yes, but Alhaitham is an emotionally stunted bastard who can't see what's right before him. Why should Kaveh entertain it? He'd be treating Alhaitham, as far as he's concerned, and his artist's fingers are put to better use with men who give him the time of day.

A flimsy excuse. Alhaitham calls him back, time and time again—and it's not as though Kaveh has actually gone and fucked anyone else as of late. Not that he needs to know it. Kaveh refuses to give Alhaitham the satisfaction of that knowledge.

"Haitham—"

"Aren't you curious?"

It is cruel to pick on Kaveh's enjoyment of utterly ruining Alhaitham in the sheets. "I… that's—"

"Hm."

Kaveh feels annoyance rise in him again. "Fine!" He turns back to his draft and begins to furiously scribble at it. "But I'm going to be awful. You'll be crying at the end of it because I'm planning on torturing you."

He doesn't miss the way Alhaitham's mouth twitches behind his cup, the most subtle curl upwards on the left side.

Oh, fuck you, thinks Kaveh.

It does not go according to his plan.

Kaveh meant to be teasing. A little mean. He'd edge Alhaitham cruelly until he begged for something else, and Kaveh would get to spin the narrative, slapping in with a big 'ol "Fuck you," to the face (and ass, he supposes).

But Alhaitham ruins it. He just has to look so good spread out on Kaveh's fingers. Clinical his ass—there's nothing clinical about this, from the way that Alhaitham greeted him warmly with a kiss, to the way he now shudders under his touch.

Kaveh knew this was a bad idea. He's down bad. Has been for too long and it seems to be a persisting problem. Alhaitham's no help with his soft sighs and the way he grinds against Kaveh's fingers. Alhaitham's rim is tight. There's too much oil, dripping down his thighs and into the sheets. Kaveh can't stop staring at the way it stretches around his knuckles.

Alhaitham moans. He's face down, ass in the air, nose buried into the crook of an arm. His other hand curls into the sheets.

"Is it truly that good?" asks Kaveh, schooling his expression into something stoic.

"Hah," Alhaitham breathes. "Mhmh…"

His insides are warm and inviting. Kaveh already knows this, having shoved his cock in enough times. But he's never taken the time to explore. Their trysts are typically rough tumbles in the sheets and quick showers afterward. And, while Kaveh might stay to sleep, casual touches are hesitant. He's certainly never… serviced Alhaitham in such a way. He's never been asked to.

The right spot was easy enough to find. Kaveh isn't entirely a bumbling fool. Took only a moment to curl his fingers, their tips sweeping over the spongy bundle, which he keeps doing.

Alhaitham chokes at a particularly strong jab. "Don't—"

"You want me to stop?"

"No." Alhaitham tries to hide his red face but Kaveh still catches it and smirks. "The—the point—" Oh, he's struggling to talk. Kaveh's fingers keep on with that incessant grind, eyes locked in on the way Alhaitham squirms on his hand. "Fuck," curses Alhaitham. "The point is to drag it out, to—to see—Oh, mnnh—"

Kaveh eases up, taking pity. "Right. You aren't supposed to come yet. Are you sure this is about milking this damn thing? Or do you just want to be edged?" Either way is a delicious prospect. He spreads his fingers and watches how Alhaitham's rim spreads, smooth and tight around his knuckles.

"Fuck you," snaps Alhaitham tersely. Ah. So there's a little fight left.

"Fuck you, I think," replies Kaveh dryly. "You're the one who came to me." He sweeps his fingers across Alhaitham's prostate again, pressing into the meat of it. Not as hard as before. If anything, not hard enough, just a teasing touch that leaves Alhaitham pressing against his hand for more.

"Torture," says Alhaitham when Kaveh pulls back, leaving him high and dry. "Stop teasing me."

"No, I told myself that I would. If you're going to come to me with such an asinine request, I decided that I'd make it worth my while." Kaveh's fingers pull out entirely and he spreads Alhaitham's asscheeks, watching his hole struggling to close.

Slick, pink insides on display. His hole clenches, though still loose and puffy. Looks delicious. He wonders what Alhaitham would do if he dips forward for a taste—

No, no, this is punishment. For Alhaitham. Kaveh's prize is his eventual demise. He's determined to reduce Alhaitham to a whining, keening mess, and Kaveh thinks that he's quite nearly there. He smooths his thumb over the furl of Alhaitham's ass, watching it twitch.

More oil. Three fingers this time, which makes Alhaitham gasp. His thighs are so tense they feel like rocks. Kaveh drags a hand down one. "Relax," he mutters. "You're going to squeeze my fingers off."

Alhaitham clenches tighter just to spite him, judging by the glare he throws over his shoulder.

Kaveh gives him a cool look. "Rude. And to think I'm helping you feel good."

"I barely feel it."

Oh? Kaveh's gaze narrows. "That sounds like a challenge," is his too-casual reply. Two can play this game of bickering. For a moment, Kaveh pitied him. "You've brought this upon yourself."

"What—oh."

Kaveh doesn't drive into Alhaitham's prostate hard. He taps his fingers against it, just barely digging in. Pressure that Alhaitham can feel. Just barely enough to bring him to the edge of madness. A tight breath escapes his chest at the slightest movement of Kaveh's fingers rolling over those nerves. Over and over. Too slow. Not quite enough.

Alhaitham seems frustrated. His cock is hard, hanging between his thighs, dripping precome into the sheets. His balls are drawn up tight. "Kaveh," he says.

Kaveh ignores him and just sweeps his fingers over the spongy nub repeatedly. Sometimes a little more. Sometimes a little less. He never ceases his movements, he just brings Alhaitham to the edge before he backs off again, Alhaitham's impending orgasm cruelly staved off.

He is a delicious sight, too. Alhaitham. He whimpers into the sheets, hoping the cotton will hide it. He presses back into Kaveh's hand, trying to chase more but fails every time. Kaveh just watches the way his fingers are swallowed by his ass, cheeks spread and wet. He listens to the slick sound of them pumping it; of Alhaitham's annoyed grunts and breathy sighs in vexation.

Kaveh could watch this for a long time. He should do this again—they should definitely do this again. His cock is hard in his trousers, aching and untouched. Kaveh digs the heel of his hand against it, stifling a groan by biting at his lip.

Alhaitham notices. He snorts and says, "Are you getting off on this?"

As if he wouldn't. Please. "That's a little cruel, Haitham," murmurs Kaveh. He truly is a fool if he thinks Kaveh would go entirely unaffected. "You're spread out before me on my fingers. And listen to the sounds you make. Unlike you, I'm not made of stone."

"I'm not—" Alhaitham's words die in a strangled cry as Kaveh's fingers twist inside him. "Kaveh. Kaveh—"

His precome is thin and liquidy, dripping from his cock like a fountain. Kaveh drags a finger down his balls, watching them twitch, before sinking lower and across the length of Alhaitham's dick. "At least this guy here is honest."

"Please." What a quiet hiss. Kaveh's gaze slides to Alhaitham's face to see it burning red with strain. "Kaveh, please."

"I wanted you to beg." Kaveh grins, shifting his hand until his fingers are lodged right where they need to be, and his thumb is pressed to his perineum on the outside. His other hand slips into his trousers to pull out his own cock. A gentle stroke across his length, following the pace of his fingers in Alhaitham's hole.

Alhaitham's insides writhe. They squeeze his fingers tight, undulating, sucking them in. Kaveh thinks of his cock being wrung dry instead.

"I'm going to—" Alhaitham sounds close. Frustrated. He fucks back against Kaveh's fingers, riding them, trying to force the angle. Kaveh lets him. He watches Alhaitham take his pleasure and strokes his cock to the sight of it. A wonderful turn this study has taken. Kaveh isn't much of a researcher, but he's an artist, and this is a sight that he can paint. He'll surely dream of it for days.

Pleasure burns in his gut, white-hot. "On my fingers," says Kaveh with sweetness because as much as he pretends he isn't, he is fond of this. Of Alhaitham. And maybe there's a sort-of dream there, the want Alhaitham's warm in the truest of sense. It's easy to imagine. They're nearly there, and it isn't the first time Kaveh has thought this. "I want you to come on my fingers alone."

For all his barbed words Alhaitham always falls quiet and sweet when he needs to. Wholly selfish—particularly so when it comes to Kaveh. A little possessive. Quiet and judgemental when out and about, and he sees Kaveh getting a little too close to others. And Kaveh is selfish too, which is why he's here, indulging in this nonsense.

"Of course, I'd rather fuck you," Kaveh then purrs. "For research, you said. Prostate milking." He digs his fingers into that fleshy bulb, and Alhaithm cries out into the pillow. "I have to wonder, Haitham, just what is the reason for the study? You're a linguist. There's nothing useful about this unless it's for… personal growth."

Alhaitham wriggles against his hand.

"So that's it, then?" Kaveh's thumb smooths circles over Alhaitham's perineum. "You just wanted me to touch you." Not a question, but a statement.

Alhaitham refuses to answer. Kaveh looks at him, head tilted. His fingers pull away just slightly, taking that burning pressure away from where Alhaitham wants it. "Kaveh." He sounds annoyed. Offended, even.

"I'll be honest. I only agreed to this because I wanted to fuck you on my fingers until you begged me to come. So, in return, you should be honest too. You came to me specifically."

"Yes." The word comes out punched, breathless.

"You wanted my fingers, specifically. You wanted me, specifically—"

"Yes, yes, just let me come. I'm—I'm—" Alhaitham grunts, throwing his hips back against Kaveh's hand.

Kaveh laughs. "Oh, you must be desperate to beg so quickly." He leans forward and kisses the swell of Alhaitham's asscheek. "You can come whenever you want, it just needs to be from my fingers only."

Alhaitham sighs in relief as Kaveh's fingers press insistently against his prostate. Over and over, sweeping over the bundle of nerves. Alhaitham's cock twitches, leaking against the bedsheets like water dripping from his slit.

All Kaveh can focus on is the way Alhaitham's ass clenches around his knuckles. How he moans under the swift drive of Kaveh's fingers, thighs tense and shaking the closer he barrels towards orgasm. There's a puddle underneath his wet and messy dick, the sheets ruined and flooded with his precome.

Kaveh's own cock aches for release. He jerks it with a slick hand as he watches Alhaitham fall apart on his fingers.

Alhaitham is quiet when he comes. A long, drawn-out moan; a breathy sigh as he spills into the sheets, finally. Kaveh's fingers slow their movements, just resting against that sensitive spot inside.

"Archons," mutters Kaveh, the hand on his own cock speeding up. He squeezes it tighter, trying to mimic the way Alhaitham's ass clamps around his fingers. "Fuck, you look so good. Haitham."

Kaveh sits up on his knees. Pulls his fingers out of Alhaitham and pulls an asscheek to the side, watching the way that his hole tries to clench tight. Wet, pink insides. Loose and sticky with oil. Fuck. Kaveh bites his lips and fucks his hand until he spills himself all over Alhaitham's ass.

He expects Alhaitham to shoot him an annoyed look over his shoulder. Instead, Kaveh finds a heated look, eyes-half slitted, pupils blown wide with arousal. Kaveh drags his thumb through his come splattered all over Alhaitham's skin. "I—"

"You missed."

Kaveh meets his gaze slowly. "Oh?' He resists the urge to scoop up his come and shove it into Alhaitham's hole. "Does that mean you want more?"

"Occasionally, a second trial is necessary." Then, Alhaitham's gaze shifts, softening softly. "Kaveh, I just want you to fuck me," he admits.

Kaveh tuts at that. What an insufferable man. "All you have to do is ask. No need to make up false studies." It takes nothing for his cock to be hard again. Kaveh uses his come and oil to slick his length, groaning softly at the thought of slipping inside.