Chapter Text
The storm had knocked out the power again. Dean hated these nights — not because of the dark, but because of what the dark did to his brother.
Well. Stepbrother.
Sam had always been strange, but ever since the incident at that abandoned church, he hadn’t been the same. He’d come back colder. Sharper. Hungrier.
And he looked at Dean like he knew things he shouldn’t.
Tonight, the house was dead silent except for the steady creak of the hallway floorboards. Dean’s pulse ticked up. He knew that sound. Knew who it was.
The door to his room swung open, slowly.
"Dean," came Sam’s voice — but it was deeper now. Slick with something unholy. "You awake?"
Dean sat up in bed. “What do you want?”
Sam stepped in, shirtless, body carved with shadows. His eyes shimmered faintly red, like embers. Not completely human. Not completely him.
“I just came to check on you,” he said, lips curving. “You always get… twitchy when the lights go out.”
“You’re not yourself.”
The thing inside Sam grinned. “Oh, I am. Just more honest now.”
He stalked closer, slow, like a predator. The air grew thick, heavy with heat. Dean’s breath hitched as he tried to look away, but the demon inside Sam had this pull — an aura that crawled under the skin and whispered filthy little invitations.
"You ever wonder why he always watched you?" the demon purred, kneeling on the edge of the bed. "Your precious brother? He wanted you. Dreamed of you. And now…" He leaned in, mouth grazing Dean’s ear. "I do too."
Dean’s back hit the headboard, caught between fear and arousal. His sweatpants were betraying him. “This isn’t right…”
“But it feels right,” the demon murmured. “Doesn’t it?”
A clawed hand — or was it still a hand? — trailed down Dean’s chest.
"You're shaking," the demon said, amused. "Should I stop? Or are you going to let me show you just how deep this connection runs?"
Sam's breath ghosted over Dean’s neck, hot and tinged with something unnatural. Dean’s fists clenched in the sheets, every muscle tight. His skin buzzed from proximity, from the wrongness of it — and how right it felt beneath that.
“You smell like you’ve been thinking about this,” the demon murmured through Sam’s voice. “Thinking about me.”
Dean gritted his teeth. “You’re not him.”
“No,” the demon said, smiling against his throat. “I’m more. And I know every filthy little thought he had about you. Every time he looked at you when you were wet out of the shower. Every time he thought about your mouth.”
“Shut up,” Dean whispered, voice raw. His cock twitched, straining against the thin fabric of his boxers.
“Oh? That get you hard?” The demon chuckled darkly. “You can’t lie to me, Dean. Your body speaks louder than you ever could.”
Sam's hand — still his hand, but more commanding, more precise — traced the edge of Dean’s waistband. “Say the word and I’ll stop. But if you don’t… I’ll take care of you in ways your brother never had the guts to.”
Dean’s heart pounded so loud it drowned the storm outside. His mind screamed for restraint, but his hips betrayed him, bucking just slightly into Sam’s hand. His lips parted around a shallow breath.
“…Fuck it,” he said. “Do it.”
That was all the invitation the demon needed.
In one fluid motion, Sam slid his palm down the front of Dean’s boxers, fingers curling possessively around his hard cock. The heat of his grip made Dean gasp, hips jerking up into it. It wasn’t just the touch — it was the feel behind it. The demon didn’t just want him. He knew him. Knew how to stroke him just right, how to tease the slit with the pad of his thumb, how to curl his fingers until Dean’s legs were trembling.
“Good boy,” Sam purred. “I knew you’d feel better with your brother’s hand on your cock.”
“Stop calling him my brother,” Dean groaned, biting his lip.
“But that’s what makes it wrong,” the demon whispered, mouth sliding down Dean’s chest, licking a slow trail to his navel. “That’s what makes it so fucking hot, isn’t it?”
Dean barely managed a breath before Sam tugged down his boxers, exposing him fully. The air hit his slick head and made him twitch — and then Sam’s mouth was on him.
Warm. Wet. Devouring.
Dean threw his head back with a strangled moan. “Fuck, Sam—”
Sam hummed around him, tongue swirling in lazy, confident circles. His eyes glowed faintly as he looked up — not pleading, not shy — but possessive. As if Dean already belonged to him.
And in that moment, with pleasure flooding his veins and shame drowning beneath it, Dean let him have it. Let the demon take him, guide him, claim him with every sinful flick of his tongue.
Sam’s tongue curled around the underside of Dean’s shaft like he was savoring something forbidden — slow, methodical, maddening. Dean’s back arched off the bed, hands tangled in the sheets like lifelines. Every time the heat coiled low in his stomach — every time his thighs started to tremble and his moans grew desperate — Sam stopped.
Pulled back, licked his lips, and smirked.
“You're so fucking easy to read,” the demon said, voice thick with amusement. “So needy. But we’re not done playing.”
Dean growled, breathless. “Why do you keep stopping—?”
“Because he never got this far with you,” the demon said, crawling back up Dean’s body until they were face to face. “And I want to draw out every second of what he’s only ever imagined.”
Dean blinked, dazed. “Sam… thought about this?”
The demon’s grin spread slowly, deliberately. “More than you know. Want to hear what he wanted? The first time was in the pool. You were sixteen. Wet. Laughing. The way the water clung to you… He couldn’t stop staring.”
He slid a hand between Dean’s thighs again — warm and practiced — and began stroking him with unbearable control, just enough pressure to make him twitch, but never enough to tip him over.
“He used to jerk off to the idea of your mouth,” the demon purred. “Wished you’d catch him. Fantasized about what you’d do if you liked it. You ever wonder why he always walked in on you changing?”
Dean’s moan broke halfway through, half frustration, half arousal. “You’re… a sick fuck—”
The demon chuckled and dragged his tongue up the side of Dean’s cock. “He is the sick fuck. I’m just finally giving you both what you wanted.”
His mouth engulfed Dean again, slow and deep — but just as the pressure rose again, just as Dean's toes curled and his hips bucked and his whole body screamed for release — Sam pulled off. Again.
Dean let out a strangled cry, thighs trembling. “Please—”
“Not yet,” the demon said, lips brushing Dean's wet, aching tip. “You don’t get to come until you beg. Until you admit you’ve wanted this too.”
His hand pumped slowly, cruelly. “Say it. Tell me you’ve thought about your stepbrother’s mouth. Tell me you wondered what it would feel like to let him ruin you.”
Dean’s whole body was on fire, straining on the edge of orgasm, but denied — over and over — and it was driving him insane.
He swallowed hard, shame and lust fighting in his eyes. Then: “I thought about him. I fucking wanted him.”
The demon stilled, eyes glowing brighter.
Dean groaned, grinding up into the demon's grip. No. Sam's grip. He looks down and found the demon staring back at him, Sam looking at him with lust clouding his eyes. He knows it's the demon, but at this point, he doesn't care. “I used to jerk off thinking about his hands. His voice. His mouth.”
Sam’s smile turned feral. “Good boy.”
He went back down — and this time, there were no more interruptions.
Dean came with a broken gasp — hips jerking up, hands scrambling for anything to hold as his entire body locked and shuddered. Hot pulses of release spilled over Lucas’s tongue, but the demon didn’t stop. He moaned around him, dragging out every spasm, sucking gently until Dean whined, twitching from the over-stimulation.
It was too much. It was perfect.
“Fuuuck, stop—” Dean gasped, but his voice was weak. Pleading, not commanding.
Sam pulled back just enough to speak, his lips slick, his eyes dark with something primal and inhuman.
“Oh, no,” the demon murmured. “You said you wanted him. You admitted it. You thought that would be the end?”
His tongue flicked out again — teasing the head, slow and deliberate. Dean’s entire body jolted. His cock was still hard. Still aching.
“I haven’t even shown you what I can do yet.”
Dean moaned, a trembling, helpless sound. His brain was foggy — the orgasm had hit him like a freight train, but the demon’s touch didn’t let the high fade. Instead, it built again. Turned sharp. Needful. His skin felt too tight. His breath too shallow.
“How…?” he whispered.
“Because I’m not just in his body,” the demon said, dragging his hand down Dean’s chest. “I’m in his mind. I feel everything he buried. Every filthy, aching thought he had about you.”
He leaned in, pressing his lips to Dean’s jaw.
“He used to dream about this. Waking up in your bed. Slipping under your sheets. Pretending it was a mistake when you moaned.”
Dean’s hips bucked up involuntarily. His cock was already twitching again — aching to be touched, teased, ruined.
“I know you dreamed too,” the demon whispered. “You thought about your stepbrother wrapping his lips around your cock. Didn’t you?”
Dean nodded, dazed, breathless. “Yes… yes…”
Sam nodded with Dean, his mouth grazing Dean's jaw. “You wanted his hands on you. Wanted him to break the rules. Cross the line.”
A single finger traced along Dean’s slit — feather light and torturous. “You were both cowards. Until now.”
Dean’s eyes fluttered, overwhelmed and turned on beyond reason. “Please… don’t stop.”
Sam— or the thing inside him — grinned like sin itself.
“Oh, baby,” he said, voice velvet and fire. “We’re just getting started.”
He slid back down, mouth open, tongue ready to pull Dean into another round — and this time, he didn’t tease. He devoured.
And Dean? He didn’t want it to stop.
Dean lost track of time. It stopped mattering. All that existed was touch, heat, and the wet, relentless pull of Lucas’s mouth.
Every time he came, he thought it would be the last — that surely his body couldn’t take more. But the demon didn't let him rest. Each orgasm was stolen from him, teased out with cruel perfection. His mind shattered in waves of pleasure, rebuilt only to break again.
The demon’s tongue lapped up every drop with reverence. Like worship. Like fuel.
Dean trembled uncontrollably, sweat-soaked and overstimulated, mouth open in a silent cry as his cock spasmed again — untouched this time — brought to the brink by words alone.
“That one,” the demon said, licking his lips. “Was from when Sam watched you jerk off through the crack in your door. He wanted to walk in and make you finish in his mouth.”
Dean whimpered, his thighs quivering. “He… he saw that?”
“He watched all the time.” A low chuckle. “Touched himself while imagining you begging for it. Just like this.”
Another orgasm ripped through him — sharp, brutal — and the demon moaned as if feeding from it. His body glowed faintly at the edges, and the room felt charged, like lightning had settled in the walls.
Dean was ruined. Raw and desperate, his mind fogged by lust, pain, longing.
The demon kissed his stomach, then his chest, crawling up until their foreheads touched.
“I can feel him now,” the demon whispered. “Sam… He’s awake. Watching. He wants to stop, but he can’t. He doesn’t want to.”
Dean’s eyes fluttered. His hips still rolled, seeking more friction, more of that unbearable pressure. “I… want him.”
“I know,” the demon purred. “I’ve tasted the way his name breaks on your tongue. You want him now. Not me.”
His fingers wrapped around Dean’s cock again — and this time, he stroked it like he meant to ruin him for good.
“Then call to him.”
Dean moaned, louder now, unable to hold it in. His body shook as another climax crested, but this one came with something more — a pull. A weight in his chest that opened and ached and burned.
“Sam—” Dean gasped.
The demon’s grin faltered. Just for a second. As if the name struck somewhere deeper than flesh.
Dean arched off the bed, crying out, “Sam, please—!”
And as he came again — harder than before, nearly blacking out from the force of it — something cracked.
A flicker behind those glowing eyes.
A voice. Shaky. Human.
“...Dean?”