Chapter Text
Keith knows what he’s doing.
He knows why this book was hidden away in the Citadel’s most restricted section, and even hidden within that, shoved cleverly behind a book about the Great War and a frighteningly thick volume on the medicinal properties of human flesh. He knows why finding it took months of careful, innocent questioning and hours of sneaking about in the night and careful surveillance and eavesdropping in places Keith was never meant to be.
As a novice, there were many places he was never meant to be. No matter that he’d excelled above and beyond all others in his class, no matter that he’d passed every exam and trial with flying colors, no matter that he’d become a legend in his own right. They still told him, in soft and condescending voices as if he were a damn child, that there was nothing to be done, nothing at all. No one knew a thing about what happened in Kerberos, or what had happened to the brave heroes who hadn’t been seen since. No one would help him get to the bottom of it, and it had all reached a breaking point when Iverson threatened to terminate Keith’s scholarship if he kept snooping.
So Keith got what he came for, the little black book no one was ever meant to find, and stopped snooping.
Because now, he’ll have someone else to do all the snooping for him.
The situation isn’t ideal, Keith thinks as he slits his palm open and methodically draws the pentagram on the floor, placing the necessary items one by one into each point of the star. But considering the circumstances, he thinks he’s done alright for himself. More importantly, for Shiro.
That’s what he has to keep telling himself – this is all for Shiro. He resolutely does not think about what this ritual entails as he stands, incense lit, items placed, blood drawn, and begins to chant the long, complex spell from memory, because if Keith is going to do this, he is going to do it right.
Shiro will forgive him, when all of this is said and done. Or maybe he won’t. Either way, Keith will have done what it was he set out to do, and Shiro will be alright. His own feelings don’t factor into the equation.
The room darkens, candlelight snuffs into blue smoke. Outside, Keith swears he can hear the distant rumble of thunder, though that seems a tad overdramatic. He forces himself to breathe and keep chanting, sucking in a sharp breath when he finishes and the symbols on the floor flare to life, bright-white and glowing, the items incinerating instantly, the incense blooming in a strong, overpowering miasma before dying out altogether. The center of the pentagram is wreathed in shadows, but they aren’t menacing – they’re curious, flickering outwards experimentally, like hundreds of black tongues, tasting the air.
Keith calls the being’s name in the most authoritative voice he can muster and it laughs, as if it finds it hilarious that he thinks he holds any power over it by using its name, a name which is in all likelihood not its true name, because something this powerful would never allow a secret so dangerous to be preserved in a book, however hidden that book might be.
Keith knows the book was hidden not for the being’s sake, but for his own.
You are young . The voice is ancient, and Keith feels it in the depths of his mind, searching to the point of invasion. But not a child. More laughter. As foolish as one, though .
“I summoned you here to bind you, not to chat,” Keith retorts, and the voice falls silent, clearly displeased by his attempt to command it.
You? Bind me? A pretty thought, the voice coos, shadows rising higher, higher, too high, fuck – it’s breaching the main circle. Keith discarded all of his protective charms and pendants beforehand, knowing it was a risk but also knowing it was as necessary if this was to work. But maybe he should have kept something, at least a ward or two...though he doubts his novice wards would hold their own against this thing.
Keith was afraid something like this would happen – no. He is not afraid. He cannot be afraid, because if he is, then this thing will know. It knows too much already.
“Yes,” Keith says, and raises his hand. “I wish to make a contract with you.”
Hmm. How do I know you’ll be worth my time? Lovely little face, but what really matters is what’s within .
Keith grits his teeth against the innuendo as it chuckles at its own joke, rising ever higher. “You will do as I say,” he snaps. “Now –”
I don’t like your tone, the voice says, and breaks through the pentagram altogether.
Keith is slammed backwards, the wind knocked out of him as he hits the wall with terrifying force, surrounded by the shadows, which are slowly but surely taking shape, looming over him in the broad silhouette of a horned man. Keith glares up at him, it, whatever, and yellow eyes gleam back, a wide mouth full of jagged white teeth opening; it lunges for him.
Keith’s inferno spell catches the shadow square in the chest and it staggers, yellow eyes widening, jagged teeth settling into a small, intrigued smile. So you do have some spark in you . That all you got?
Keith snarls and strikes out, springing to his feet and following the inferno with three lightning strikes in quick succession; he knows he’s making too much noise but hopes and stupidly prays that the being will keep the others from hearing, keep its utterly forbidden presence here a secret. Keith could be imprisoned for life for simply having the bloody pentagram on his floor, he could be hanged if found with the book, he could –
“Get out of my head!” Keith shouts, flicking his wrist sharply upwards and sending a wall of red flames into the shadow’s path.
No, the shadow purrs, I like it here. And a huge, clawed hand closes tight around Keith’s throat, hauling him up against the wall, his feet kicking weakly as he squirms and punches uselessly at the being’s flexing arm. But enough to stay…? That remains to be seen.
Keith gurgles furiously, heat building in his chest, prickling along his skin, and the yellow eyes widen again as flames cover Keith’s body, a spell he has only used once before and which left him feeling like, well, he’d just set himself on fire. But the being is entranced, unbothered by the fire burning its hand, and tilts its head in genuine awe as Keith becomes a living conflagration. Alright, it says, so there’s more than just a spark in you.
“Hrrkk,” Keith chokes, and the hand on his throat loosens enough for him to gulp in hot, sulfurous air as the flames flicker out, but doesn’t release him. It’s throwing him a bone, and Keith, desperate, seizes it. “I want a contract,” Keith repeats in a low rasp.
Why?
It’s a simple enough question, and Keith tries to provide a simple enough answer. “I lost someone dear to me,” he says, “and I want to know what happened to them. In Kerberos.”
Kerberos, it repeats, drawing the word out long. I see. Is that all?
“I want to bring him back,” Keith says.
There is a long silence. The dead should stay dead, it finally says, and Keith is surprised by the thoughtful, almost sad quality of its tone.
“He might not be dead,” Keith says. He doesn’t want to imagine the possibility.
There are worse fates than death.
“Listen,” Keith snaps, “will you do it, or not?”
You want me to find out what happened in Kerberos and you want to bring back your lover?
Keith flushes. “He wasn’t my –”
Don’t lie to me. He would have been. You wanted him to be. And he will be, now.
And to Keith’s horror – and, yet, it is most definitely not all horror that he feels – the shadow settles on a shape, a familiar shape, the shape of Shiro. It hurts how accurate the illusion is. He – it – smiles, and Keith’s heart stutters.
“That isn’t what I meant, don’t twist my words,” Keith mutters, refusing to meet its eyes, Shiro’s eyes. “I want him back.”
“I know, I know,” Not-Shiro soothes in Shiro’s voice, and Keith tamps down the urge to scream as the thing keeps smiling at him, soft and sweet and an absolute fucking trap. He holds still as one hand cups his shoulder gently. “I agree to your terms, Keith . Do you agree to mine?”
Keith takes a moment to answer; his throat is dry and his chest aches. Surprisingly, Not-Shiro waits for him, waits untils he whispers, “Yes,” and then, when it still doesn’t move, “yes, fine, I said I agree!”
“Seal it with a kiss?” Not-Shiro asks, mock-innocent and hopeful, and Keith glowers, knowing far more than a kiss is required, goes up on his tiptoes, and kisses him. It.
Whatever.
Keith hates that he’s imagined this moment over and over again, and yet it’s never been as good as this; this reality that is not a reality at all, kissing this thing wearing Shiro’s face, Shiro’s body, Shiro’s skin, sliding a warm hand up to his cheek and into his hair, lips smooth and firm and perfect, tongue wet and sloppy as he presses deeper. It’s too easy to just think of Not-Shiro as Shiro , the Shiro who Keith had always wanted so badly.
And Keith, damn himself, melts into it, lips giving easily under Shiro’s, slumping against the wall as a solid, strong body presses against his own, oh, oh, yes, that’s Shiro’s cock.
Keith’s thighs part with little actual thought and Shiro’s chest rumbles in approval; he breaks the kiss to murmur, Greedy, aren’t we? and Keith hates that it makes his own cock pulse in his briefs, trapped against the increasingly uncomfortable seam. Shiro just chuckles again, and then palms are sliding under Keith’s thighs and lifting him up, walking them across the room to Keith’s bed, and Keith can only cling weakly and try not to panic, try to tell himself, for Shiro, for Shiro.
He’s tossed onto the bed unceremoniously, and braces himself as Shiro clambers over him, clothes fading away from his body like mere smoke, touching Keith’s shirt and pants and doing the same to that fabric, too, whisking it away. Keith’s panic climbs higher; he didn’t except them both to be naked so quickly, but here they are. His vision is swimming and he can barely see Shiro’s body, ridiculously beautiful, sculpted, cock curving up huge and hard and red over his rippling abdomen. Somewhat hysterically, Keith wishes he’d chosen someone slightly smaller to fall in love with.
“Hush.”
The word is soft, not mocking in the slightest, and Keith blinks blearily. Shiro peers down at him, and it really looks like Shiro, it really – he swallows back the lump in his throat. Fingers card through his hair. “Keith,” Shiro says. It makes Keith want to cry .
“Just,” Keith whispers, “just get it over with, will you –”
“Was that an order?” Shiro asks mildly. His forelock of hair hangs into his face, black as soot, and suddenly Keith can’t speak, can’t look at him. It’s too much, too painful to remember, and his cock softens as he lays there inert, remembering what could have been, hurting .
“Oh,” Shiro says, and frowns. Keith closes his eyes, and when he opens them again, cautiously, after a strange buzz of magic through the air, he stares.
It’s Shiro, but...older? Different. Shiro, but with white hair hanging into his face instead of black, grown out a little longer, and with a faded pink scar slashed over the bridge of his nose, and other scars, too, scattered across his skin like rose petals, but most notably he’s lost his right arm. It’s been replaced by a metallic prosthetic of some kind, and when Keith hesitantly reaches out to touch, Shiro doesn’t stop him. Keith supposes they will be doing a lot of touching from here on out, anyway.
The prosthetic is warm, not cold as he’d expected.
“Do you like this better?” Shiro asks.
Keith stares up at him, blank. “Does it matter?”
Shiro’s answer disarms him. “Of course. This is your contract, after all.”
“And my soul you’ll be taking,” Keith mutters.
Shiro shrugs. “There’s quite a ways to go before we get to that part, darling.”
Keith winces. “Don’t call me that.” Shiro would never call me that.
“Mm,” Shiro says, considering. “What, then? Dear? Sweetheart? Or, hm, how about – baby ?”
“Don’t,” Keith warns, but his face is turning steadily redder; Shiro has him right where he wants him.
“Baby,” Shiro purrs, and nudges his scarred nose against Keith’s, and Keith can almost forget he’s an unimaginably powerful interdimensional fiend from the depths of Hell.
Almost.
Then Shiro pulls away, eyes glinting with the golden light that reminds Keith what it really is, and says, “You really are a virgin, aren’t you.”
It’s not a question.
“That was what the ritual specified, did it not?” Keith counters.
It’s not an answer.
“Yes, but,” Shiro noses into Keith’s throat and Keith wonders why he hasn’t been flipped and fucked already, “few actually fit that particular ‘requirement.’ It’s become more symbolic than anything else. You, though…” He pushes himself up on one flesh arm and one metal, and smirks. “This is going to be fun.”
Keith eyes him with apprehension.
Shiro’s smirk falters. “You aren’t just going to lay there and look at me like a kicked puppy, are you?”
“I don’t —” Keith scowls. “What do you want me to do?”
“Well,” Shiro drawls, “I want you to stop pouting, for one. This needn’t be some awful ordeal, Keith. It’s really supposed to be the opposite.”
“Then make me,” Keith says. He’s not in the mood for sweet talk and flirtation. He knows what this thing is capable of.
Shiro blinks, laughs, and then moves down Keith’s body. Startled, Keith tries to sit up but is held down by a single finger on his chest, and then there’s warm breath feathering over his cock. Shiro grins at him from between Keith’s thighs, lowering his large body to suckle teasingly at the head of Keith’s rehardening cock. Keith jerks, eyes widening, absolutely not expecting that. He had prepared himself for a quick, rough, careless coupling, not this .
“Quick and careless? You wound me,” Shiro murmurs, licking under the foreskin until Keith squirms, deft fingers playing around the base and tracing over veins in light, maddening touches. “Rough, though...that, I can do. Another time.”
Keith shakes his head, hands fisting into the sheets. “Just — hurry up —”
“But it’s your first time,” Shiro croons, laving his tongue in a long, wide, wet drag down the side of Keith’s cock as it bobs up and fills out, a pearly bead of precum caught on the demon’s lips. “Don’t you want it to last?”
“Just fuck me!” Keith hisses. “I don’t want…” He gestures vaguely to Shiro’s mouth on his cock.
“You don’t want it to feel good?” Shiro sits back on his heels and shakes his head in disapproval. “Well, that’s too bad. Because I plan to see you come at least thrice before the night is through.”
Keith gawks at him. “Three times?! I can’t possibly!”
“You can,” Shiro says with surety, “and you will. I’ll make number one easy for you, hm?”
And he sucks Keith’s cock into his mouth in its entirety.
Keith barely manages to muffle his cry in his palm, hips stuttering up into warm wet heat and the lengthening tongue curling and flicking relentlessly, drooling saliva which runs in rivulets down Keith’s cock and pools on his balls. Shiro spreads the wetness around with the metal hand and chuckles in a torturous series of vibrations; Keith moans and squeezes his eyes shut.
Shiro squeezes his thigh. “Look at me,” he murmurs, pulling off and licking his messy lips.
Keith shudders, struggling to keep his eyes open as Shiro sinks back down again, the head of Keith’s cock bulging out in Shiro’s cheek, then Shiro’s throat works around it, constricts without even the slightest gag, and Keith can’t look away. He’s imagined this before, imagined Shiro on his knees in the library, the two of them hidden in a distant alcove, Keith’s nails digging into lacquered wood and Shiro’s scalp, hips working his cock shallowly into Shiro’s mouth, pink lips stretched wide —
Shiro groans, pleased, and Keith knows he heard the fantasy. He knows there’s nothing he can really hide from this thing, and accepts it with a kind of dull defeat, panting breathlessly as Shiro hollows his cheeks and guides Keith’s hands to his head. Keith’s fingers close around the forelock and tug, sharp, his other hand scrabbles uselessly through Shiro’s undercut, struggling to find purchase. He never does.
Keith’s toes curl and his back arches up from the bed as Shiro swallows around the tip and lifts Keith’s thigh up and over his shoulder, leaving Keith open and exposed and coming with a shaky gasp that feels torn from his throat. Shiro takes it, milks his cock dry until Keith is twitching from over-sensitivity. Shiro pulls off, but does not back off; gives Keith’s softening cock a few more fond licks as Keith flaps his hands uselessly to ward him off.
“See?” Shiro purrs, sitting back on his heels, still stroking Keith’s cock, preventing it from softening fully. “That wasn’t so bad.”
“S-stop,” Keith pants, “oh, f-fuck –”
Shiro stops touching Keith’s cock but moves closer, close enough that his cock drags over Keith’s thigh, just a brush, but Keith flinches and eyes it as if it will bite him at any moment. Shiro snorts. “You know, one would almost think you hadn’t realized you were making a contract with an incubus.”
“I realize that,” Keith mutters. “But this is…” Wrong. Not him. It was supposed to be with him.
“Ahh,” Shiro says, knowing. “Very well. Shall we pretend, then?”
“Pretend?” Keith echoes. “How –”
“Keith,” Shiro says, voice lowering, expression serious, eyes fixed on him and only him. “I want you, so much.”
Keith’s gut roils. “You are a cruel being,” he whispers.
Shiro’s brow creases, he strokes Keith’s hair out of his face. “Cruel? Because I denied you this for so long?” He shakes his head. “I was denying myself too, you know. You have no idea how many moments I wished to just…” Shiro sighs, longing, and kisses him.
Keith is weak; only the weak make deals with demons; and so he kisses back. He hates himself for wanting to pretend, to play along, because he knows that will make this so much easier.
Worse, but easier.
Shiro settles more heavily atop him as their tongues meet, and Keith moans softly into the kiss, wrapping his legs around Shiro’s waist, unthinking. Shiro hums and grinds downwards and Keith’s nails scrape across Shiro’s shoulders, raising thin pink lines on already-scarred skin. “Baby,” Shiro murmurs against his lips like a secret, and Keith’s lashes flutter, heels digging into his lower back. “I wanna hear you,” Shiro adds, mouth slipping down Keith’s jaw, teeth dragging over his neck and tongue lapping at his throat. “Be loud for me, baby.”
“Nngh,” Keith grunts, shaking his head furiously, “shut up ,” and then lets out a strangled yelp when Shiro bites down on one of his soft nipples, tugging at the pink bud between his teeth as Keith writhes and swears. “Augh! What’re you – why –”
“You’re prettier when you’re flustered,” Shiro tells him, licking and sucking alternately over his nipple as it peaks into hardness, teasing at the other with his metal fingertips. “Let’s try something – I think you’ll like it.” And before Keith can so much as open his mouth in protest, the metal hand is whirring with vibrations, buzzing against Keith’s nipple and through his chest, and it’s warm, too, heating up steadily, coupled by Shiro’s tongue as he leans down to lick and mouth happily at Keith’s nipples again.
Keith gasps wordlessly, his cock hardening in stages, nudging against Shiro’s erection as it does so. The friction makes Keith whine, and Shiro continues to play with his nipples and rub his cock over Keith’s until Keith is flushed and aching again, shocked by his body’s eagerness...and yet barely shocked at all. It may not really be Shiro, but it looks like Shiro, feels like Shiro, and Keith would do anything for Shiro.
“Anything, huh?” Shiro chuckles, low and dark, and Keith glowers at him. There’s no fire in it.
He tenses as the metal fingers’ buzz fades and they glide over his skin, bypassing his cock altogether and dipping instead between his thighs, over the tight pucker of his hole, circling. Shiro watches his face, gaze heavy. Keith bites his tongue and spreads his legs wider, hoping to rile up the stupid thing into finishing this already, but Shiro just laughs at him.
“I think you’ll find I can be very patient,” Shiro tells him, magic swirling through the air and gathering a slick substance on the metal fingers, clear warm ooze that tingles on Keith’s skin. “More patient than any human, anyway. Mm, I could make you beg for it. What a sight that would be.”
“Don’t,” Keith breathes, and he sounds pathetic even to his own ears. His eyes are watering and he refuses to call them tears.
Shiro’s eyebrow arches, but he shrugs, and says, “Rain check on that, then,” and rubs his slick finger over Keith’s hole. “Have you touched yourself here, before?” he asks, as casual as if he were discussing the weather.
“No,” Keith mutters. He’s wanted to, but he hasn’t.
Damn, he needs to control his thoughts.
Shiro smirks. “Good luck with that. I think you should do the honors.” He takes Keith’s wrist and guides his right hand down, lifting up a leg for better access, and Keith opens and closes his mouth like a fish. Shiro snaps his fingers and more of the slick ooze drips from thin air over Keith’s hand, coating his fingers liberally in it. “Well? You wanted this over with, get it over with.”
Keith bites his lip, glares, and blindly searches, feeling awkward and filthy when his index finger finds Shiro’s fingers, then his hole, and he presses as hard as he dares, working it inside. The sensation is uncomfortable and strange, and Keith shifts, looking resolutely at the ceiling, sliding the finger inside up to the second knuckle and refusing to acknowledge how easy the ooze makes it. His body clenches too-tight around the digit, and Keith winces, gritting his teeth. This was a mistake. He thought he could do this, he thought he knew what he was signing up for, but this...he can’t do this.
“Yes, you can,” Shiro murmurs, looming over him, petting his hip. “You can do this, Keith, breathe; open yourself up for me, baby.”
Keith shudders, belly sucking in sharply, finger curling as the ooze tingles inside of him and the demon’s fingers grip his ass firmly, holding him open, allowing him to slide a second finger inside. It’s not pain, but pressure that he feels, body adjusting slowly to the intrusion, cock remaining hard and heavy on his belly. Keith glances at Shiro’s leaking erection and clenches tight again, doubtful and apprehensive.
Shiro clicks his tongue. “Relax,” he murmurs, nails turning claw as he caresses Keith’s side, hand trailing a path of heat from Keith’s hip to rib cage to throat, and Keith shivers at the unbidden thought that this thing could tear him from limb to limb if it so chose. Shiro falters, looking surprised by this particular thought, then sly. Keith wants to sink into the blankets until he disappears from this realm.
A sharp claw taps at his chin. “Huh,” Shiro says. “You like the thought of me hurting you?” Keith stiffens, fear trickling coldly down his spine, and Shiro’s lips form a small ‘o.’ “Or, no...not that, not quite. You don’t want me to hurt you, but you like knowing that I could .” Keith does not answer and Shiro grins. “That’s it, isn’t it? Heh. You humans do love a power trip.”
Keith has no idea how to explain that it’s not a power trip at all, because with Shiro it was never about power, it was never about give and take; it was only ever about looking into Shiro’s eyes and understanding quietly but completely that no one had ever looked at him the way Shiro had, and Keith had never felt for anyone else what he felt for Shiro, and probably never would again.
The demon either does not understand this or simply ignores it, because he does not comment; he just presses one of his metal fingers inside of Keith and turns up the vibrations.
Keith shouts, back bowing and cock jolting, bracing his feet on the bed as he involuntarily bears down on the fingers, two of his own and one of Shiro’s, thick and solid and stretching him wider, impossibly wide with a second. Keith pants soundlessly and Shiro relents, cooing calmingly and easing Keith’s fingers out, replacing them with his larger and more talented ones. Keith’s cock is weeping precum on his taut stomach, puddling around the pink tip with every thrumming thrust of Shiro’s fingers inside of him. When Shiro finds his prostate Keith barely processes it; his senses are already overloaded, an extra stab of euphoria is lost amidst the rest of the dizzying wave.
“Second time,” Shiro urges, twists his fingers and curls them deep, vibrations shaking Keith to the core, fizzling up his spine endlessly. Keith comes with his mouth and legs wide open, splattering across his belly and chest. Shiro giggles and licks it up, and Keith swears that through his blissful haze he can feel magic crackling through the air around them, Shiro’s skin growing hotter to the touch, charging with power.
Power from Keith, probably – with Shiro, it was never about power, but this is not Shiro, and this is all about power. Keith may be more than a little stupid, but he’s not naive. He knows how this ends.
“Don’t ruin the mood, baby,” Shiro grumbles, and flips them.
Keith, stunned, braces himself on Shiro’s chest and stares down at him dumbly. He expected face-down, and now he’s on top.
“I’ll fuck you face-down another day, don’t worry,” Shiro assures, lips quirking, hands closing around Keith’s hips. “Now, sit on my cock.”
Keith says, “Sorry?”
Shiro lifts him, and Keith struggles to no avail, finding himself moved until he’s straddling Shiro’s hips properly, Shiro’s cock under him. From this vantage point, it looks even more daunting, and Keith tries to clamp his legs shut when the wide, flared head brushes against his ass. He only succeeds in straddling Shiro more securely. Keith’s cock hangs soft, messy with his own cum, and he hisses when it brushes against Shiro’s belly, hisses louder when Shiro takes it in hand.
“Three times, remember?” Shiro says innocently, batting his eyelashes. Keith still wavers, shocked, and Shiro mutters something before sliding his metal fingers back under Keith and inside him. Keith whines at the different angle, biting his lip while Shiro stretches him open, because it’s too much, he’s come hard twice in, what, twenty minutes? But at the same time, he knows he wants more, and the longer Shiro spends playing with his loosened hole, the more appealing Shiro’s cock starts to look.
No, not starts. Keith found it appealing from the beginning, but it just didn’t seem like he could take that. But now Shiro has three thick fingers up his ass, ooze squelching loud and obscene between them, and Keith almost sobs as Shiro’s right thumb rubs slow and purposeful over his cockhead; again and again, claw teasing at the slit as precum begins to flow again, Keith is going to die .
“No,” Shiro chuckles, “you’re going to sit on my cock, and you’re going to ride me until you come, baby,” and Keith moans in helpless agreement, hole gaping as Shiro’s fingers withdraw. Keith can feel how open he is; it’s absurd, but it’s even more absurd how fucking incredible it feels when the head of Shiro’s cock catches on his rim, slides in slow, then pops inside like a fat plug; Keith’s mouth falling open and head falling back as the slide continues, hot and hard and thick and full. Sharp claws scratch at his hips and Keith trembles, thighs aching from the strain as he tries to keep it slow, tries not to bottom out hard and fast and all at once like a part of him really, really wants to. He doesn’t know how long it takes, but when Shiro’s fully seated inside him, Keith can barely breathe; his chest is tight and his body is tight sheathing Shiro’s cock, but not to the point of discomfort, this time.
Shiro groans under him, eyes half-lidded in pleasure, and, to Keith’s shock, glowing gold. “Good boy,” Shiro praises, and Keith turns scarlet, cock throbbing to the beat of his rapid pulse. “Warming my cock so well – I knew you could take it.”
“Do you ever shut up,” Keith grunts, voice coming out far less steady than he would have liked. He thinks that’s fair, considering he’s currently stuffed full of demon cock.
Shiro enjoys the snark, apparently, because he says, “Why don’t you try and make me?” and shifts under him, and it’s not a thrust, not really, but Keith bounces on his cock and is momentarily stunned by the sensation. Shiro looks far too pleased with himself, and Keith, panting and flushed, rolls his hips, shallow but eager, fast, and the claws on his hips draw blood. Keith doesn’t care; he’s already given his blood to this thing, it already has all of him.
But – and this is an important epiphany, for Keith – he has all of it, too.
Shiro’s eyes widen under Keith as Keith lifts up, then comes down hard, cock slapping his stomach and breath spilling harshly from his mouth, Shiro’s cock rocking and rubbing rhythmically inside him with every movement. Keith claws at Shiro’s chest, pinches his dusky nipples between thumb and forefinger, and Shiro unexpectedly bucks, hard , and Keith cries out, writhing into it, pinching harder, hard enough to hurt .
“You little slut,” Shiro snarls, and it takes Keith a moment to realize what’s happening – Shiro’s spine buckles and spasms, every convulsion driving his cock deeper, in and out, and his skin vanishes into shadowy patches, and up close Keith can see it isn’t a void of empty black, the darkness is alive , and flickering with magic, little sparks like stars, the night sky incarnate.
The hands on his hips are rough, leathery, not like human hands at all, and Keith yelps when smooth, coiling muscle wraps around his torso – a tail, he realizes, with a blunt tip that forces its way past his lips and plunges into his mouth. Keith chokes, sucks on instinct, bewildered and overwhelmed, falling forwards in slow motion. He catches himself on Shiro’s chest, which is broadening, muscle flexing under his hands, the bed creaking under the added weight.
The tail pulses around his body, constricting and releasing, binding him, and stretches his lips around its tip as it wriggles deeper, shaping his throat. Keith drools and blinks back tears; the demon’s skin tastes sweet to the point of sickly, but he can’t stop, and he doesn’t think Shiro would let him.
Shiro’s cock is thickening and Keith is whimpering, body straining around the shifting erection which curls and strokes just like the tail inside of him, pulsing like it has a mind of its own, the head swelling wider, the base swelling, too, stretching Keith’s tender rim. Shiro’s hands cover Keith’s entire rib cage, thumbs meeting easily in the middle of his stomach, and Shiro fucks up into him relentlessly, yellow eyes glaring from a face that is Shiro but not, Shiro with the wickedly curving horns of a ram and the teeth of a predator and the tongue of a snake, and Keith thinks dazedly, This is what I’ve bound myself to .
Huge black bat wings erupt from Shiro’s wide shoulders, curling high over Keith’s head, enveloping them, and Keith wonders if he’s mad for thinking there’s something almost beautiful about the transformation.
His third climax catches him entirely unawares; Shiro’s tail is squeezing harshly around his chest and ravishing his mouth, claws are raking down his sides in a sharp sweet burn, and Shiro’s cock is splitting him open, and then Keith is screaming and coming, cock painting ribbons of cum across Shiro’s heaving chest, and Keith may have just made a contract with a creature from Hell but he feels like he’s just ascended.
Shiro groans at the sight and his tail loosens, withdraws from Keith’s mouth, and Keith slumps forward, only to be reminded at once that, yes, he is still stuffed full of demon cock. Thighs trembling and cock trying to soften, drained, Keith squirms, and Shiro groans louder, desperate, and Keith sees his eyes flicker in...confliction? Could it truly be that he’s wary of hurting Keith to reach his own end? It seems unlikely.
Shiro bares his teeth in frustration. “Come,” Keith commands, and Shiro stares at him in disbelief. His cock twitches inside Keith, and Keith squirms down onto it, gritting his teeth as it swells further, hotter, fatter. “I said, come ,” Keith growls, and Shiro arches off the bed and does, pumping Keith full of cum that is far hotter than a human’s, at least from Keith’s limited experience, and Keith moans weakly and stares as his belly bulges outwards, the demon’s cock softening slowly as it spurts the last of it deep into his gut. Fuck . Fuck, Keith is so utterly fucked, and it’s his own damn doing.
Shiro’s eyes are hungry, and Keith cannot help the pitiful whine that falls from his lips as Shiro lifts him off his cock, cum flooding out, Keith’s hole winking in greedy contractions around nothing. But then he’s straddling Shiro’s face and Keith’s eyes fly wide, and Shiro murmurs, “I said at least thrice,” before licking inside of Keith firmly.
Keith whimpers in both despair and indescribable pleasure, held up by Shiro’s flexing tail, and Shiro hums contentedly as he licks him clean, swirling his long, forked tongue through the mess of his own cum, teasing at Keith’s tender hole until he manages to coax one last, faltering orgasm from Keith’s spent cock, which he licks clean while Keith twitches uselessly, after which he finally relents. Shiro lets go and Keith collapses onto the bed beside him, nearly conking his head on the headboard. A clawed hand softens his fall.
A warm nose nuzzles at his face and Keith cracks an eye open blearily. “What?” he mumbles. “Is it done?”
“It is done,” Shiro purrs, and lifts his hand, pressing it to Keith’s cheek. Heat courses through him like electricity through copper wire, and something tugs in his chest, tugs him closer to the sated incubus. Keith is exhausted, but the magic settles within him, dormant for now. “Our contract is sealed.”
“Great,” Keith mumbles, and closes his eyes again. He does not expect to have a soft blanket draped over him, but he stubbornly keeps his eyes shut when it happens – he did what he had to, and he won’t be subjected to snuggling or whatever other post-coital shenanigans the incubus wants from him.
Four times. Good heavens.
Keith falls asleep fast, and when he awakes, late the next morning, it is to an aching body, an empty room, and all signs of the summoning erased.
But Keith stretches, winces, feels the phantom breath of infernal magic over his skin and inside him, and knows it was not a dream.