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THE DEMON OF LUST - Jeong Jaehyun x Fem Reader.
● Summary: After your friends convince you to go out for a good time, you find yourself dragged along to a popular bar. But unexpected circumstances are about to lead you straight to a very particular being.
● Warnings/Tags: Jaehyun Demon!, smut (not explicit), forbidden romance, no use of y/n.
● Words: 4.2k
● A/N: English isn't my first lenguage.
The rain fell over the city like a silent curse that night.
The neon lights melted against the wet pavement while you walked behind your friends with a half-hearted expression, hugging yourself against the chill that seeped into your bones.
"We can still go back," you murmured, your voice nearly drowned out by the downpour.
"Not a chance," Mina said, gripping your arm firmly. "You’ve been cooped up for weeks. Tonight you’re having fun, even if I have to drag you."
You sighed, resigned.
The bar in front of you glowed in hues of red and gold—elegant, but far too noisy for your taste. A luminous sign spelled out the name Neocity above the entrance. You couldn't shake the heavy feeling in your chest, a strange foreboding you couldn't quite decipher.
You didn't know that the very instant you stepped through those doors, someone stopped breathing.
Because he was already there.
Waiting for you.
Watching you.
From the darkest corner of the bar, that demon in human form slowly raised his eyes. At that exact moment, the entire world seemed to go completely silent. It wasn't a poetic metaphor; the blaring music grew distant, conversations vanished, and the thick smoke in the air seemed to freeze for a second as his black eyes locked solely onto you.
There you were again.
The impossible girl. The human with light in her blood.
He had been following you for months. Months of watching you from a distance, like an addict incapable of drawing close to the very thing that, ironically, could destroy him with its own purity. You weren't like the others. Humans usually fell before him in seconds. A single glance, a smile, the imperceptible brush of his fingers was enough to unleash an uncontrollable desire—a need bordering on obsession.
He was the demon of lust. Sin made flesh. People adored him without realizing it, surrendering to their darkest impulses under his influence.
But with you… with you, it was different.
You walked through the world with a softness he found unbearable, a cruel innocence that made something inside him burn with an intensity he had never known.
And he, a creature born of hell, had become completely incapable of tearing his eyes away from you. It was ridiculous, dangerous, humiliating. But there you were, in front of him, once again.
And tonight… tonight he was finally going to speak to you.
"We’re going to dance, you coming?" Mina said, already moving to the beat of the music.
You shook your head, despite your friend's attempts to pull you from your seat. She finally gave up and headed toward the dance floor, leaving you alone by the bar. You absentmindedly adjusted the sleeves of your leather jacket as you scanned the venue, feeling the weight of the crowd and the suffocating heat. You ordered a drink just to have something to do with your hands.
And then you felt it.
A presence behind you. It wasn't exactly physical heat; it was something deeper, a heaviness in the air that shifted everything.
You turned slowly. And you saw him. Your heart took a violent leap.
The man in front of you looked… unreal. Beautiful. Dangerously beautiful. He was dressed entirely in black, and the intricate, dark tattoos climbing up his neck seemed to take on a life of their own under the flashing lights. His skin was flawless, and his black eyes were so deep they were frightening if you looked for too long.
For a second, you forgot how to breathe. He offered a faint smile, and the world seemed to crumble.
"May I sit?" he asked, his voice deep, calm, and strangely comforting.
You should have said no. Any intelligent person would have said no. But something in his magnetism drew you in a way you couldn't explain—an urgency that overridden your common sense.
You nodded slowly.
He took the seat next to you. Instantly, the scent of his cologne—woody, warm, slightly sweet—enveloped you, drowning out the bar's smell of alcohol and tobacco.
"You don't seem to be enjoying this place very much," he commented, watching you with absolute attention.
"Is it that obvious?"
"A little."
"My friends made me come."
"Then I should thank them."
Your cheeks flushed slightly at his direct comment. He noticed, of course. Demons perceived every minuscule change in the human body: the accelerated rhythm of your heart, your unsteady breathing, the way your pupils dilated when you looked at him. He could sense the desire awakening inside you—small and trembling, but real. And it nearly drove him insane.
"What's your name?" you asked, trying to regain control of the conversation.
There was a pause. His true name couldn't be uttered in human tongue; it was ancient, violent, a name that made entire creatures tremble. But with you, tonight, he wanted to be something else—something less monstrous.
"Jaehyun," he finally replied. The name sounded all too natural leaving his lips, but to him, it felt like a white lie.
"Beautiful name."
*If you only knew what I truly am* he thought. But he smiled. "And yours?"
When you said your name, Jaehyun felt something dark twist painfully inside his chest. Because even your name sounded precious to him.
Pathetic. Completely pathetic.
Talking to him was strangely easy. Time began to slip away without you noticing; the conversation flowed as if you had known each other your entire lives. He listened to your every word with absolute attentiveness, making you feel seen, special, safe.
That was the worst part. Because Jaehyun wasn't safe. He was destruction disguised as beauty. But with you, he wanted to pretend he could be human, just for one night.
The music suddenly shifted to something slower, more sensual. Jaehyun tilted his head slightly toward you, his gaze locked onto yours.
"Dance with me."
It wasn't really a question, and yet you nodded. He guided you toward the dance floor. It was packed with people, but the moment his hands settled firmly on your waist, the rest of the world seemed to vanish. You felt an intense, almost electric heat radiating from his body. Your fingers slid slowly up to his shoulders as he pulled you closer.
Too close. Your chest brushed against his. You could feel it again: that strange, potent heat beneath his skin, like a contained fire fighting to break free.
Jaehyun looked down at you, devouring your lips, your eyes, your shaky breath. He was running out of self-control. Never before had he needed to restrain himself this much around a human. Because he didn't just want to possess you; he wanted to keep you, and that terrified him more than any infernal punishment.
"You're looking at me like you want to tell me something," you whispered, trapped in his gaze.
He smiled faintly, his face drawing dangerously close to yours.
"Maybe I do."
"And what would that be?"
Jaehyun tilted his face slightly, so close you could feel his warm breath on your lips.
"That you are dangerous."
You let out a small, nervous laugh, your heart racing wildly.
"I think you're the danger here."
Oh, if you only knew…
When his lips finally touched yours, you felt the world tilt completely. It wasn't a soft kiss, nor was it rough; it was intense, desperate, as if he had been holding back for centuries. Your hand ended up tangled in his dark hair as he deepened the kiss slowly, trapping you against his firm body.
And Jaehyun… Jaehyun was losing his mind. Your taste was addictive, warm, human—worse than any punishment he could ever imagine. His fingers tightened slightly around your waist as a dangerous darkness vibrated just beneath his skin.
For a split second, his eyes flashed a vivid red. Just a second. But you didn't see it, far too busy trying to remember how to breathe.
You don't remember exactly how you ended up leaving the bar. You only remember the rain hitting your faces, your nervous laughter, and his hand holding yours tightly as you walked hurriedly toward your apartment. And the way he looked at you in silence: as if you were something sacred, something he should have never touched but could no longer let go.
The tension exploded the moment you crossed the threshold of the apartment. Jaehyun kissed you with ferocity against the door as soon as it slammed shut behind you, enveloping both of you in the darkness of the entryway. Your hands desperately traced his neck while he held you with barely contained desperation.
Every touch of his seemed to set your skin on fire. Your ragged breaths filled the silence of the place. And yet… there was something strange about him. His body was too hot, almost feverish. The shadows in the room seemed to shift and twist on their own whenever Jaehyun lost his focus. At times, you could swear you felt something dark and alive sliding just beneath his tattooed skin.
But every time you tried to process it, he would kiss you again and your mind would simply stop working.
"Jaehyun…" you whispered between breaths, your voice trembling.
He closed his eyes upon hearing his name in your voice, fighting his own instincts. He didn't know how much longer he could hide it. The desire inside him was beginning to blend with something far more dangerous: the demonic instinct to claim, to possess. And he shouldn't do it. Not with you.
The urgency carried you both from the entryway to the kitchen. You found yourself sitting on the cold countertop while he rested his forehead against yours in the dim light. His hands moved slowly over your waist and hips with a reverence that contrasted sharply with the intensity of his gaze. He seemed to be trying to memorize your every curve, your every texture.
And then you saw it. It was only for a second, but it was unmistakable. The dark shadows on his neck began to move. It wasn't a trick of the light; they seemed to spread and writhe like living ink over his burning skin.
Your eyes widened, confusion mingling with desire.
"What…?" your voice came out as a thread.
Jaehyun cursed internally, his breathing turning husky. The darkness vanished immediately, his tattoos becoming static once more, but it was too late. You had noticed.
You backed away slightly on the counter, fear beginning to seep in. He slowly raised his eyes to meet yours, and this time, he didn't look entirely human. His black eyes glowed faintly red under the dim kitchen light.
You expected to feel panic. You should have screamed, run, done something. But all you felt was your heart racing even faster—a strange mixture of terror and an unyielding attraction.
"Who are you?" you asked in a low voice, your gaze locked onto his.
Jaehyun remained silent for several long seconds, his breathing the only sign of life. Then he smiled with infinite sadness.
"Someone who should have stayed far away from you."
But he didn't move. And neither did you.
"Tell me the truth," you demanded, your voice gaining strength despite everything.
His gaze swept over your face slowly, as if he were deciding how much pain he could cause you with a single word. Finally, he spoke, his voice deeper than ever.
"I am not human."
The air grew heavy, oppressive, and the lights in the apartment flickered for just an instant.
"Then… what are you?" your voice was a barely audible whisper.
Jaehyun held your gaze, his expression serious and tormented.
"A demon."
A heavy silence fell between the two of you. He expected fear, screams, for you to hate him and run away. But you only stared at him, trying to process his words.
"That's impossible."
He let out a bitter little laugh.
"I wish it were."
And then, the shadows in the room truly began to move around him. Dark, alive, slowly climbing up his arms like black smoke rising from his burning skin.
Your lips parted slightly. Because now you could see it: the creature hidden beneath the human skin, the raw power radiating from him. And yet… and yet he was still beautiful, in a terrifying and fascinating way.
"I should go," he said, his voice tense with the effort of restraining himself.
But he made no move to step away from you. Because he didn't want to. Because he had been desiring you for months with an intensity that consumed him. The demon inside him had already made a choice long before speaking to you.
Instead of backing away, you moved closer to him. Jaehyun looked at you, genuinely surprised by your reaction.
"You don't understand me," he murmured. "I am literally the worst thing that could ever get close to someone like you."
"Then why haven't you hurt me?"
He froze, left without an answer. Because he had never wanted to protect anyone before. Because his instinct had always been to take, not to care.
"Jaehyun…"
Your hand rose slowly until it touched his burning face. And that… that completely broke him. His eyes closed briefly against your palm, like a starving creature receiving warmth for the first time in its existence.
"Don't do that," he whispered, his voice broken.
"Do what?"
"Treat me as if there's something good in me."
Your heart clenched painfully. And before you could answer, he kissed you again. This time with something deeper, more desperate and vulnerable. As if he were damned and knew that, after tonight, there would be no turning back for either of you.
His hands moved up your curves, tracing a path dictated by absolute possessiveness. Before you could even process the heat of his touch, your jacket and shirt had already been stripped from your body, tossed carelessly out of his line of sight.
Jaehyun's hands relished the warmth of your breasts while his lips traced a trail of wet kisses that devoured your neck, descending slowly down your collarbones to the valley of your chest.
Every little gasp that escaped your lips was an addictive melody to the demon's ears, igniting a primitive, wild, and relentless side within him.
With determination, he took you into his arms. Wrapping your legs around his waist, you allowed him to guide you through the darkness toward your bedroom. During the entire journey, you could feel his intense arousal pressing hard against your center—a constant reminder of the desire consuming him.
"You're perfect," he whispered barely as your bodies fell onto the soft bed, his pinning you down with a deliciously overwhelming weight.
With superhuman agility, Jaehyun unfastened your pants and, in one swift movement, stripped the garment from you. Though you still wore your underwear, you suddenly felt self-conscious under the gaze of Jaehyun, who no longer bothered to hide his piercing crimson eyes. They were two pools of carmine fire devouring your nakedness. Seeking refuge from that intensity, you drew him back to you, kissing his mouth with devotion while his hands—slightly rough from the pent-up energy—removed the thin fabric of your panties. Your center was already responding to him, completely slick from the mere proximity of his magnetism.
"Ah!" You let out your first gasp against his lips as you felt the pressure of his middle finger forcing its way through your inner walls with a torturous slowness that made you arch your back.
It had been too long since you had experienced contact of this nature, causing your muscles to contract suffocatingly around him, locking him in an intimate, warm embrace.
Jaehyun muffled a growl against your neck, intoxicated by the delicious resistance of your body.
He began to move his fingers in a steady rhythm, exploring your anatomy with an almost mystical precision, drawing spasms of pure pleasure from you. The heat in the room grew dense; the shadows in the corners of the ceiling seemed to writhe to the rhythm of your moans, isolating the bed from the rest of the universe.
When the desire reached a point of no return, Jaehyun rid himself of the last clothing covering him, revealing a perfect, sculpted silhouette where the tattoos on his neck seemed to expand like dark veins across his shoulders and chest. He positioned himself between your legs, pinning your hands above your head with a firmness that made you shudder.
"Look at me," he commanded, his voice vibrating straight into your chest. "I want you to see the creature that is going to claim you."
You locked your eyes onto his, hypnotized by the carmine glow of his pupils. When he joined with you in a firm, deep thrust, you felt the world stop. It wasn't just a physical encounter; it was a tide of electricity and liquid fire expanding through your entire being. His every movement was intense—a perfect blend between the brutality of his demonic nature and an almost sacred adoration for your body. You lost all track of time, completely surrendered to the rhythm of his hips, his hungry kisses, and the possessive words he whispered in your ear. At the night's climax, when the pleasure became so sharp it almost hurt, Jaehyun pressed his lips against your chest, right above your heart, releasing the latent energy of his true essence in one last, desperate claim.
You felt a burning sting, a sweet and piercing pain that made you cling to his broad shoulders while he caught his breath, sealing his pact into your skin before collapsing by your side, exhausted.
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Hours later, the apartment remained in absolute silence. The rain kept drumming rhythmically against the windows. And you slept soundly amidst the tangled sheets, completely enveloped by the intense heat of his body.
Jaehyun watched your face in the dim light. Your peaceful breathing, your hand resting trustingly on his chest… something that should be impossible for a creature like him. Because demons didn't love—not truly.
But there he was. Completely lost to you.
His gaze traveled slowly down to the dark mark beginning to appear vividly just below your collarbone. It was an elegant black symbol, resembling ink spreading across your skin.
The bond.
The demonic union.
The irrefutable proof that they were now connected for all eternity.
Jaehyun closed his eyes heavily. He should have stopped. He should have left before it was too late. But it was too late. Because now he could feel you: your soul, your warmth, your very existence beating alongside his own.
And the worst part of all… was that he didn't regret it.