"Be mine, Tanjiro, and you and your family will never want for anything again."
Tanjiro hears in those words, whispered soft and dark against the shell of his ear, what Muzan doesn't say: that to refuse him would be to condemn his family to poverty, and his father to death.
But of course, Muzan would never say anything like that--never has, never needed to. Tanjiro has no real idea of how Muzan came to be involved with his family, just knows he appeared out of thin air when his father's health took a turn for the worst three years ago, and they'd had little recourse but to lean on his charity ever since.
It had been nice, for a while. He'd understood his parents' discomfort with accepting so much help from Muzan, but the man just seemed so kind, so generous, and Tanjiro had been dazzled by his handsome refinement, his secret smiles and electric gaze. Sometimes Muzan would bring sweets for the little ones and then sneak Tanjiro and Nezuko some too when the kids weren't looking, as if to say "I know you're too old for sweets, but is anyone really?"
Back then, Tanjiro had felt like he was being acknowledged. But now the memories sit, heavy and cold, going sour in the back of his mind.
Muzan leans forward.
Tanjiro forces himself not to move away. Not when he feels the man's hot breath against his face, nor when a hand cups his cheek, nor when he feels the movement of Muzan's lips just a hair's breadth away from his own, asking, "Have you ever been kissed, Tanjiro?"
Tanjiro's eyes meet Muzan's intense gaze for a moment, then skitter away, mortification gnawing at him as he whispers, lips trembling, "Never."
Muzan's breath hitches one moment, and the next, his mouth is on Tanjiro's, stealing his first kiss--or not stealing, he's paying for it isn't he? Has been paying for years, and has patiently waited to collect his prize.
Muzan's lips are warm, and soft, feel luxurious against Tanjiro's chapped, bite-worried mouth. It doesn't feel bad, the gentle ebb and return of pressure, the hand in his hair, cradling the back of his head.
It feels good--should feel good, it's his first kiss and it's with a beautiful man who has doted on him for years, he should be swooning.
Mostly though, Tanjiro wants to cry.
Muzan pulls away at last, though his hands don't leave Tanjiro, keeping him where he wants him. Tanjiro tries to keep the distress off his face, keep his eyes from welling up with tears, but he's no good at any sort of lying, never has been. There's no way Muzan can't see his reluctance, must be insulted by this visceral rejection.
But when he looks at Muzan again, all he sees is dark, poisonous satisfaction swimming in his too-bright eyes.
(Sometimes, Tanjiro swears he's caught them glowing. But that can't be; Muzan's not some demon, even if Tanjiro is finally starting to glimpse his monstrous nature.)
"Open up for me, darling," Muzan commands, his thumb toying with Tanjiro’s bottom lip. This time when he moves in, it's with purpose, his mouth firm on Tanjiro's, his tongue swiping at the seam of Tanjiro's lips, his hands and the heavy lean of his body coaxing Tanjiro into laying back on the arm of the couch.
The couch--where Tanjiro had taken tea with Muzan's late wife, read story books to his daughter while babysitting. Oh god, is it going to happen here? He's going to give himself over to this man, bought and paid for, right here?
Tanjiro opens his mouth, tries to say, "Wait--" but Muzan uses the opening to deepen the kiss, pressing closer to Tanjiro as Muzan’s tongue invades his mouth, licking at his own, overwhelming him with new, slick sensation. Hot, he's starting to feel hot.
Tanjiro has no idea what to do. He doesn't want to do anything, but he's here now, for his family, for his father. They'd never ask this of him but he has to, he can't put them at risk for his own pride, his own selfishness. He's the eldest son, he can handle a tongue in his mouth.
Hesitantly he moves his own, trying to match Muzan’s movements, unsure of how to make this good, worth the millions invested in him, in this moment. Whatever he's doing must be okay, or maybe it's just the effort that's pleasing, because Muzan groans into his mouth, attacking all the more fervently in response.
Tanjiro feels Muzan's hands travel down his body, shivers at the light touch as it moves over him, unbuttoning his uniform blazer, then down to slip under his dress shirt, his under shirt, until Muzan's fingers finally hit skin. Tanjiro lets out an involuntary gasp at the touch.
Muzan's hands feel so cool. Even with how hot his mouth is, the desire burning bright in his eyes as he takes Tanjiro's mouth, his hands are almost chilly against Tanjiro's feverish skin.
Too fast, isn't this too fast? He's only just been kissed, for the first time ever, and now?
Goosebumps break out over Tanjiro's skin as those hands slide up, skin-hungry, eating up the smooth plains of his torso, his carefully tended to fingernails scraping lightly over the gentle swell and dip of adolescent muscle. Tanjiro's shirt gets rucked up higher and higher, exposing his midsection to the cool air of the living room.
Tanjiro gasps against Muzan's mouth when a hand makes it up to his chest, pinches a nipple. The sensation of it is unexpected, a bright flash of pain. Muzan pulls away, gives Tanjiro room to take in deep, desperate breaths. Muzan watches his face as he does it again, takes to torturing Tanjiro's chest with an expression of dark enthrallment.
Tanjiro tries to bear it, doesn't quite know how he's supposed to--every pinch, every harsh scrape of nail over sensitive flesh leaves Tanjiro shivering, filling the room with high, pitiful sounds. His face is burning, eyes wetting with shame-filled tears.
Muzan stares down at him, licks his lips. His eyes travel down, from Tanjiro's wide-eyed expression, to his half-exposed torso, and further.
Horror floods Tanjiro as grew realizes that, somewhere in all of this, his body has started responding, his cock beginning to fill out in his trousers.
Tanjiro watches as Muzan's hand starts making its way down, slim fingers trailing down his abdomen, and he can't help it, he clenches his legs together, closing off, babbling, "Wait, please, I-I haven't ever--"
Muzan looks down at him like he wants to eat him alive.
"Truly, you are such an innocent," he says, eyes ravenous. But he backs away then, stands up, and for one delirious moment Tanjiro really thinks Muzan will let him go, relief and something like fond gratitude surging through him.
So he just feels that much more stupid when Muzan scoops him up off the couch and says, cradling Tanjiro to his chest, "Of course, such a special occasion deserves a bed."
Tanjiro hides his face against Muzan’s shoulder as he suppresses a sob. Muzan's hand makes small, soothing motions against his back, and Tanjiro hates that it comforts him, hates that years of familiarity have trained him to curl up closer to his chest, his steady-beating heart.
The creak of a door swinging open then clicking shut alerts Tanjiro to the fact that they've most likely reached their destination, but it still shocks him to find himself dropped down onto a bed.
Muzan's bed. It has to be. The scent of the man is overwhelming here.
Tanjiro opens his eyes to an unfamiliar ceiling, in an unfamiliar bed, drowning in a too-familiar scent. He feels the bed shift under him as Muzan joins him, crawling up between his legs, until he's leaning over Tanjiro yet again, his hand taking Tanjiro's chin in his grip and forcing him to meet his eye.
Muzan's grip is hard, harder than before, almost bruising. Tanjiro wonders if he's made a mistake--an even bigger one--by letting himself be brought here, wonders if things are about to escalate more painfully in the seclusion of Muzan's bedroom than they might have in the living room.
He can handle it, Tanjiro reminds himself. Whatever comes his way, for the sake of his family he will handle it.
Muzan grins down at him, bloodthirsty.
"Got your fire back, I see," Muzan murmurs, thumbing at Tanjiro's lower lip. "Though I hope you don't see me as an adversary. I know it's overwhelming, but I'm merely expressing my desire for you." Muzan releases his face, uses his forearm to brace himself against the bed as he moves in closer, their bodies pressing together from chest to groin, the heat and pressure willing Tanjiro's body to arch up, seeking-- "Then again, it overwhelms me too."
Muzan bites into his neck at the same time that he rolls his body down, hard and filthy, against Tanjiro's.
"Muza--ah--!" Tanjiro's body reacts without his mind, his hands fisting into bed sheets, his thighs clenching around Muzan's hips. Good, it feels good, and awful and sick, and Tanjiro feels so hot, wants to crawl out of all his layers, leave even his skin behind to escape the perverse warmth rushing through him.
Muzan grinds down against him, again and again, the press of his hardness lewd and obvious against Tanjiro's groin, so close to his own reluctant arousal. He can hear the slick sounds of Muzan's mouth working against his throat, licking and sucking at the patch of skin he'd just abused with his teeth. Every one of Tanjiro's short, quick breaths drags in a lungful of Muzan: his desire, his amusement, his sense of conquest. Tanjiro writhes, his movements near-involuntary as his body reacts blindly to a level of stimulation it's never quite felt before.
Even when Muzan lifts off of him, sitting back between his legs, the memory of his weight, the heavy heat of his stare, keeps Tanjiro pinned and his breathing shallow. "I think it's time to do away with all this," Muzan says, tugging at the fabric of Tanjiro's shirt. "Well?"
With a flush of humiliating heat, Tanjiro realizes that Muzan expects him to undress himself. No, doesn't just expect it but knows with complete confidence that he will.
Slowly, Tanjiro brings his trembling hands up and, one by one, opens up the buttons of his shirt.
"Good boy," Muzan praises, his voice low and full, his hand massaging his own arousal through his trousers. Muzan makes for such a lewd, beautiful picture, and Tanjiro tries to focus on that, to turn it into wanting. He has to do this, for his family, but couldn't it be worse?
That line of thought doesn't help much, just makes him think how much easier this would all be if he felt differently about Muzan; if he desired him, loved him. But somehow, despite Muzan's generosity, his years of indulgence, Tanjiro just can't find anything in him to love.
Tanjiro shimmies his way out of his blazer and dress shirt, shivering as Muzan's hands return to him, sliding over his torso, pushing his undershirt up as he goes. After a moment's hesitation, Tanjiro pulls that off too.
"Exquisite," Muzan says, eyes eating up Tanjiro's exposed skin. He smooths his hands up Tanjiro's front to his shoulders, then curls them, until his blunt nails are pressed into Tanjiro's skin, and drags them back down.
Tanjiro gasps, his body instinctively pressing back against the bed to escape Muzan's claws. But of course there's no getting away; Tanjiro can only watch as red lines bloom across his chest in the wake of Muzan's fingers.
"You mark easily," Muzan says, letting one hand go still as the other draws patterns over his skin, "it's very satisfying."
Tanjiro flushes, squirming, over-aware of his skin and everything touching it. He doesn't know why that statement fills him with such shame. The feeling only deepens when Muzan brings his hand down, sliding one fingertip from the dip of his collarbone, over his sternum, past his navel and down through the dark trail of hair to the button of his pants, bisecting him with one thin red line.
This time, Tanjiro knows he can't refuse him, no matter how much he wants to. So he looks to the ceiling instead as Muzan opens his fly, works his pants and underwear down his hips and off his body.
For a moment, Tanjiro is alone, untouched on the bed, and it doesn't feel real at all. To be laid bare on these fine sheets, surrounded by the scent of cigarettes and expensive cologne and something like malice--it all feels like an awful dream.
Then, Muzan is back, his hands on Tanjiro's body, flipping him over onto his stomach. Tanjiro scrambles, tries to get up, but a hand comes down on his neck, keeping his face and shoulders down to the mattress. Hot tears of mortification well up in his eyes as Muzan holds him down with one hand, and with the other, drips something cool and slippery down his back. It's lube, most likely, and Tanjiro tells himself to be grateful for at as Muzan drags a finger down Tanjiro's spine, through the trail of liquid, scooping it up and bringing it to his goal.
Tanjiro can't help the fearful whimper that leaves him when he feels Muzan's fingers at his entrance.
"Even here you're gorgeous," Muzan says, his voice like poisoned honey as he massages Tanjiro's hole. "Tell me, have you ever penetrated yourself before?"
Tanjiro's face goes hot at the question. "O-of course not!" He shares a room with his brothers for goodness sake, he hardly ever has the time or the privacy to pleasure himself at all, never mind experiment beyond the basics.
He smells the spike in Muzan's arousal at that, wishes he could say with any level of verity that he had, wishes he could say that he’s had a dozen lovers, a thousand kisses, anything to make himself less appealing to the man behind him. Every bit of him, of his body, of his experience, of his life, that Muzan takes pleasure in feels tainted, wrong, for having attracted attention like this, from a man like this.
Muzan pushes a finger into him without warning. Tanjiro jerks in his hold, eyes going wide at the unfamiliar intrusion, the odd sensation of being breached. His breath hitches, tears finally start dripping down from his eyes as Muzan pumps his finger into him, steadily sinking in just a little bit deeper with every thrust. Tanjiro tries his best to keep still, to muffle his whimpers. It's for his family, he's reminds himself, if he just bears this (forever, for as long as Muzan desires him), then they can be happy, healthy, together.
(But with his face buried in a rich older man's sheets, his ass in the air as Muzan forces a second finger into him, Tanjiro feels unworthy of that togetherness. They would be horrified by this, horrified by him. 'I'm sorry,' he thinks, 'I'm so sorry, mother, father--' )
Suddenly, he feels the hand pinning his neck lift, instead moving to rub comforting circles into his shoulders. His pitiful body reacts to the pseudo-kindness like a child to a lullaby--relaxing, his muscles shuddering with the release of tension.
"That's it," Muzan coos, sweet and patronizing, "If you don't relax this will hurt more than it needs to."
A pathetic cry leaves Tanjiro's throat as a third finger is added too soon after the second one, his body rocking with the motion of Muzan's thrusts into his hole. Hysteria claws at his insides-- this is wrong, he shouldn't be here, he shouldn't be allowing this, why is this happening?
Muzan's fingers leave him. Tanjiro goes still.
His brain doesn't register Muzan moving behind him until he feels what must be the head of cock at his entrance, his hand gripping Tanjiro's hip bruise-tight, and then he's pushing in, inch after terrible inch, until he's fully sheathed in Tanjiro's body.
Tanjiro can't breathe. It's too much, he's too full, too surrounded by Muzan's scent, the heat of his body at his back, inside of him.
"C-c-can't," he tries to say, his voice choked up. Tears stream steadily down his face and he can barely feel them. "Can't, please, I--"
"Ssh," Muzan murmurs against the shell of his ear, "You can, and you will, and in return you'll have everything you've ever dreamed of."
Tanjiro sobs openly when Muzan starts moving, the sensation of someone moving inside him completely foreign to him. His legs go to jelly just a few thrusts in, and when he sinks to the bed, Muzan follows, fucking him into the sheets. That's its own torture, his cock now forced to grind down against the bed with every thrust, his mind getting lost in the whirlwind of sensation overtaking him. Even worse, the pleasurable, torturous friction on his cock seems to make his body more accepting of the overwhelming feeling of having Muzan inside of him. Not every sound that leaves him is one of pain, not ever shiver that rips through him one of disgust.
Triumph rolls off of Muzan in waves, a sadistic satisfaction permeating his scent, encapsulated in every drop of sweat that slides down his body. His thrusts take on a savage quality, brutally hard and fast, spearing his cock into Tanjiro over and over. He pulls Tanjiro's head back by the hair, the shift in their bodies enough to make Muzan hit something inside Tanjiro dead-on where before he'd just teased it, so when Tanjiro cries out it’s from more than just the sting of his scalp.
Muzan pulls Tanjiro close enough to lick the tears off his cheek, reveling in his distress, in his overwhelm. "You're mine now," Muzan pants into his ear, his pace unrelenting, his voice dripping with hateful glee, "You'll only ever be mine, do you understand?"
Tanjiro opens his mouth to say something, can't.
Muzan tightens his grip on Tanjiro's hair, grinds into him hard so his cock drags against the bed sheets in a way that's horrible, delicious. "Answer me, you whore, tell me who you belong to."
"Y-you!" Tanjiro cries out, knows he has no choice; knows it's true, "I-I'm yours!"
Muzan groans, forces Tanjiro's face back down into the bedding, his thrusts turning vicious as he pounds into Tanjiro, the stimulation to Tanjiro's cock, to that strange place inside of him constant and incredible and miserable all at once. Tanjiro's whole body shakes as he feels himself getting forced closer and closer to orgasm, his body euphoric where his mind is in shambles, and it hardly takes a minute more before he tenses, his skin too small for the jumble of his experience as he comes, crying, against the bed sheets.
"I knew you'd get off to it," Muzan sneers, never faltering for a moment as he chases his end in Tanjiro's body, "Knew you'd take me perfectly. Perfectly mine, Tanjiro."
It could be minutes or hours before Muzan comes inside of him, Tanjiro's mind is too far gone to know. He just knows that eventually, Muzan rolls off of him, moves away to the clean half of the bed, and starts smoking. It's the acrid scent of tobacco that rouses Tanjiro, gets him to rise, shakily, to he knees. He feels Muzan's spend inside of him, seeping out of him.
"Go clean yourself up," Muzan says, voice back to being cool and unconcerned, "You're filthy. The en suite's that door." Muzan waves his lit cigarette vaguely to the left, then takes a long drag off it as he watches Tanjiro stiffly make his way across the room.
Tanjiro couldn't be more grateful to make it into the bathroom, to stumble into the huge shower stall, and turn the water on, hot as it'll go. He wants to scrub his own skin off, scald away the memory of Muzan's touch.
He grabs for for the body wash, eager to clean himself, then pauses at the scent.
Of course, it's what Muzan uses, so it smells like him.
Tanjiro stands there for a moment, a horrid, earth-rending scream building up in his chest, climbing up his throat, ready to break through his teeth to get free. Tanjiro swallows it down.
He's the eldest son, he's done what he had to do for his family. He can take this much.