A/N: So here is a one-shot I wrote for the anon prompt 'incubus'. It's kind of dark, considering the nature of incubus and how they view humans. Demon!Kurt. Future fic, supernatural, angst, mention of Huntbastian. Rated M.

He's gorgeous. Flawless. If you see him, partaking in the nightlife - weaving amongst the fabulous, overindulgent people of the city - he may just seem like another glamorously dressed hard-body with just one exception. He has no soul. He's poison, and death eventually follows where he goes. He preys on the beautiful and the righteous. Those who would not stray fall at his feet. Those who would not hurt another would gladly kill for a night with him. Nothing grows when he is near, except for the overwhelming desire to be his.

He collects stalwart people and ruins them; turns them into his willing slaves just for the honor of a night in his bed, but after that, there's no turning back. No human is ever good enough. No happiness as fulfilling. People waste away their lives seeking him out, or praying that he will come to them, but no prayers have ever reached him. He is a demon of the basest desires, fallen, feeding off the raw need that doesn't always give itself freely.

But that's okay, because Kurt lives for the challenge, and he finds one in a man who is truly and helplessly in love - a green-eyed Adonis wrapped blissfully in the arms of another lover.

And Kurt can't wait for his chance to tear them apart.

He follows them home from a night spent out enjoying the town. He can read their minds. See into their hearts. One is called Hunter, but the one the demon wants is named Sebastian.

Sebastian.

Sebastian, who volunteers weekends at the local children's hospital.

Sebastian, who calls his mother three times a week.

Sebastian, who is deeply in love with his boyfriend of two years.

In fact, Sebastian is planning to ask Hunter to marry him soon.

Kurt found Sebastian just in time. When love is ripe like this, it's so much fun to destroy. Kurt grins, vicious and cruel, teeth pointed for just a second as he gives in to his nature and fully enjoys the rapture of this moment.

He waits until the two climb into bed together, dizzy from a little too much tequila and a lot of erotic dancing, and watches from the window as they make love. Kurt is intrigued by the way Sebastian seems to submit to Hunter. In Kurt's eyes, Hunter is nothing special – a few muscles, an obvious dye job, capped teeth and pale (to the point of almost colorless) green eyes. Sebastian lies beneath him and moans almost predictably, but Kurt notices how Sebastian squeezes his eyes tight when Hunter isn't looking. Kurt smiles.

Kurt knows that game.

Sebastian is imagining someone else.

That's not to say that Sebastian is disloyal. Kurt wouldn't be so attracted to him if he were. But Sebastian has a type, something different from Hunter that really gets him off. Kurt searches his fantasies and immediately comes up with a façade that can overwhelm Sebastian - the visage of a man right out of his dirtiest dreams.

Kurt is not a patient demon, and even after a few minutes of intercourse, Kurt becomes bored with the show. He speeds things along, insuring that Hunter gets his 'happy ending' and drops quickly to sleep, while Sebastian is left, disappointed and wanting.

Sebastian sighs, too frustrated to keep from crying his distress, but too tired to do anything about his condition, and he falls asleep unfulfilled.

He falls asleep vulnerable.

Sebastian drifts in and out of sleep, between the point of awake and dreaming, when Kurt makes his move, creeping in like a venomous snake, curling along the floor, an intangible wisp of black smoke darkening the air. He approaches the bed and shifts, taking a corporal form, much like the one he plans to adopt to seduce his new lover.

Kurt paces around the bed from one side to the other, first regarding Sebastian, then Hunter, wondering what in the hell Sebastian could possibly see in this plasticky-looking man. Kurt resists the urge to invade his dreams, lock him in a nightmare of losing his precious Sebastian, of seeing him walk away without a backward glance.

But Kurt decides to save that for later.

Kurt turns when Sebastian whimpers, knowing his time has come. He rescues his beautiful human lover from a troubled, stressful sleep, climbing on top of him, entering inside of him, filling his dreams with visions of his body moving over him. Sebastian can see eyes, blue as ice but filled with an almost other-worldly warmth and affection, staring down at him, met by a smile that can put the sun to shame and skin of pure alabaster, as if it was carved from stone. Sebastian can feel this amazing body all around him, sliding against him, wrapped around his neglected cock, pulsing inside him. Every inch of him is covered in a sensation of skin and tongue and wet and heat and he almost cries out into the darkness.

"Are…are you really here?" he asks instead, speaking more with his mind and his heart than his mouth.

"Yes," the demon reassures him as he continues to fill Sebastian's body with his addictive pleasure. "I came here for you. Just for you. And now you belong to me."

For some reason, this is what Sebastian has been waiting for, even laying here beside his lover, the man he swore he would marry. Sebastian chooses this dream instead, and lets it envelope him. Along with the almost never-ending, blinding ecstasy that builds and builds with almost no end in sight, leaving him exhausted and sated in a way he's never known, he feels something small and sharp, like a tiny thorn, worm its way into his heart. But that feeling is so insignificant in the face of his momentous release, he allows it to linger, to let it burn, with little more thought about it than a brief recognition of its existence.

Sebastian falls asleep in the arms of an invisible man from his dreams while deep inside his innocent soul a tiny burr is left.

The next morning, Sebastian finds it hard to concentrate on even the tiniest task. Buttoning up his shirt, putting a Windsor knot in his tie, even styling his hair takes more thought than he can muster. He still feels the heat of that incredible night. It crawls beneath his skin, itching away at places he can't scratch, places he can't reach. It's inside him. He needs to find it.

Sebastian's heart changes, craving his demon lover to the detriment of all else. The first victim of Sebastian's deviance is Hunter - poor, clueless Hunter. He tries to comfort his love, tries to hold him, but Sebastian yells and pushes him away. Sebastian calls him worthless, calls him an asshole, throws every barb he has and comes up with a few new ones, and by the time he's done, Hunter leaves in tears, vowing silently to never return.

Sebastian doesn't go to work. Why does he need to work anyway? His trust fund will last him for the rest of his life if he uses it carefully. Food and rent are really all the worldly comforts he needs. Something to keep him going and a place to sit and wait – that will do.

Sebastian calls it a night at around 7:30 – just an hour after sunset. He hasn't eaten a thing. He hasn't left his apartment. He spent the day in a chair pushed up to the window, letting the minutes tick by. Life went by around him even if he wasn't an active participant.

Kurt knows all this. He settled in a corner of Sebastian's apartment and watched. He made Sebastian wait, let the little thorn needle its way deeper until Kurt was sure that Sebastian belonged to him without question, that he was willing to give up his entire world, his own happiness and the happiness of those around him, just for another taste of Kurt.

Kurt waits until the darkness is at its peak, and Sebastian has slipped into a restless sleep, afraid that his dream lover has abandoned him. He doesn't mourn all the things he's given up. He only despairs for this one thing that he's afraid he's lost. He gives in to self-loathing, curses himself for not being enough, despises his looks and his voice and his clothes. He breaks himself down to only his faults.

It's this moment that Kurt chooses to come to his rescue.

"You're here," Sebastian sighs with a wash of relief when those crystal blue eyes come into view. "I was afraid I wouldn't see you again."

"Poor Sebastian," Kurt coos condescendingly. "I'll never leave you."

Sebastian nods, content that this gorgeous man is telling him the truth, and for his loyalty and obedience, Kurt takes him over, bleeds into him until his essence fills Sebastian's body. He races through his veins, wraps around his spine, and completes him from the inside of his soul to the surface of his skin. Every one of Sebastian's senses is filled with him – he tastes him on his tongue and smells the masculine scent of him with every intake of breath. He feels Kurt all over, brushing against his lips, covering him with his warmth, fingering him deep and caressing his aching length with his mouth. Sebastian arches his back and cries out. This is what it is to be devoured, consumed, taken for everything he is with nothing left behind. Sebastian's body is taken to its limit, again and again, cumming with the demon's voice singing sweetly in his ears, making dark promises, spouting poetry and sonnets which might be empty and void except for one thing…

This demon, in this one insignificant human, this mortal plaything, has found a way, his own way, to love.

It's a cold comfort, though. Demons can't really, truly love, and even if he could, he doesn't have anything but lies to offer.

But Sebastian belongs to Kurt, and Kurt doesn't share his things.

There is nothing left in life for Sebastian but this – the waiting for his demon lover to return, filled to the brim through the day with hatred and self-doubt, until the sun sets and he gets to bask in the complete fulfillment of his demon's empty love.