A/N: I blame 13x21 with its insinuation that angels can ejaculate their Grace for this story.
Lines from the show appear in this story, and they're from episodes 5x03 "Free to Be You and Me", and 5x10 "Abandon All Hope".
WARNING: This story contains non-con elements.
"I want to say yes."
Five words. Five words he knew he'd had to say. Five words he wished he could take back. Because of those five words Sam found himself in a situation he had never considered, something that had never once crossed his mind - but if it had it would have filled him with fear. Sam had been possessed before, and he was friends with Castiel, so he was sure he knew how this whole thing worked. The entity, whatever form it took - smoke, light - went in your mouth, and then from there took control of your entire body. And he'd been pretty sure that the essence of the other being always, always came out of their mouth as well. But now the Devil had ordered him to get on his knees.
"What?" Sam asked.
They'd been discussing this deal, discussing the Horsemen's rings, which Lucifer unfortunately knew about, and then he'd said this one thing.
Dean reached out and grabbed his arm, as if wanting to pull him back.
"I'm not," - Sam began, scrunching up his face as he thought of how to continue - "swearing fealty to you if that's what you want."
Satan's eyes glimmered with eager excitement, a warning to a predator's prey that it should turn tail and run.
"Oh no, of course, nothing like that," he murmured, as he circled him now, making Sam feel trapped, cornered. Cold seeped from his very presence, to the point where Sam's body was tense, near to shivering. "See, you have your demands, I have mine. You want Dean left alive, I'm sure, and I, well, I want something else." His hand was on his shoulder now, making Sam stiffen and swallow roughly. Sam tilted his head towards him, somehow meeting that ancient and terrible gaze as Lucifer said, "Don't worry, you'll still end up possessed. Just need to work for it."
Sam's mind was drawing to horrific conclusions, and really, this was Lucifer, so it would make sense for him to suffer something such as this, but he didn't want to say it, didn't want to make it real.
"You first came to me in my bed. That wasn't an accident, was it?"
"Ah, he has a brain!" Lucifer declared to Dean and the dead bodies that lay about them.
"Sammy," Dean whispered, trying to get his attention, trying to speak with him.
Sam knew what he meant: Don't do this.
Sam turned to his brother as Lucifer hovered nearby, hands clasped together and rubbing his thumbs as if he couldn't wait to touch him, to have him.
"Dean, I have to."
"Yeah, Dean," Lucifer said. "Let the man sacrifice himself." A cold hand was now at the back of his neck. "Your brother made his choice."
"But he didn't consent to that!" Dean argued. "Getting on his knees and opening his mouth for you."
Lucifer leaned against Sam, as if this was just a casual conversation and they weren't in fact discussing assault and the end of the world.
"He did say yes. Y-E-S. Three lovely letters strung together to make my favorite word. Well, no is fun too, under certain circumstances," Lucifer now said to Sam, hand up by his mouth as if he was telling him a secret, though he spoke loud enough for Dean to hear. "I love it when they squirm."
It was all too much.
"Get off me!" Sam cried, trying to shove him away. Lucifer let him, but just barely.
"Look, boys, it's not so bad. Sure, my brother Castiel didn't tell you about all the ways Grace can leave the body, but it's gotta get in Sam somehow, am I right?"
"Do it some other way!" Dean growled.
"Quiet, or I'm going to decide you don't need your tongue. Now, Sam, enough stalling." He cupped his face in his hands and Sam snarled at him, trying to draw away, but Lucifer held him tight. "The end of days is upon us. The Apocalypse is here. It's now or never, Sam Winchester."
Too much saliva was building up in Sam's mouth, and he was busy looking at the floor, unable to face the evil before him. But he was his true vessel. No one else could do this. He met the Devil's gaze.
"Dean lives?"
"Cross my heart and hope to die."
"Sammy, don't!"
Lucifer ignored Dean, a wide smile breaking out on his face. He inhaled deeply, and then commanded, "On your knees, Sam."
Sam had expected his body to fill with adrenaline, had expected to feel the bright beat of fear in his heart, giving strength to his blood. But instead, something else took him, a fear he'd never felt before. It was numbing, freezing, and all hope of fighting even if the situation would allow it left him. Weak, trembling, he lowered himself to the floor before Satan, his brother calling his name.
Dean's hands were on him now, on his shoulders.
"Sammy, get up. You gotta get up. We'll do it some other way. The world isn't worth this."
Sam's motions felt slow, his body tingling as he tilted himself to face Dean.
"I'm giving myself to him, Dean. Don't you get it? This, this'll be nothing compared to what he does to me after."
"You can't know that."
"He'll… He'll be in me. All of me."
"Sam, I can't just stand here and watch him… watch him use you."
Lucifer let out a dramatic sigh, sending a cold wave through Sam's body, and he pressed himself back against his brother.
"Oh, but you won't be just standing there," Lucifer informed them.
"Excuse me?"
"You have the very special job of holding him steady."
"If you think I'm gonna-" Dean began, but then suddenly, Lucifer snapped his fingers. Sam was forced to face forward, body completely rigid, Dean's hands now clasped tightly on his head as he stood behind him. Sam soon realized he could move, but just barely, his brother's hands held steady by some power he couldn't see.
"Good boy," Lucifer commended, as if Dean had done as he'd asked of his own accord.
Sam's upper lip trembled, and he was breathing heavy, feeling as though he was suffocating, struggling for breath. He closed his eyes, not wanting to see, but having already gotten a glimpse of Lucifer's hardness.
"Sammy, it's gonna be okay," Dean breathed. "I'm right here."
Sam flinched at the sound of a zipper being undone.
"So, Dean, since I want all my focus on how lovely your brother's mouth is, I'm going to release you, but if you even make me think you're going to let go of my vessel, he loses some teeth. Got it?"
At his words, Sam placed his hands over Dean's, a silent plea to keep them there, to do his job and to hold him steady. He even squeezed a little, an I'll be alright to the brother who knew he was lying.
Motion, Lucifer moving closer to him, and then Sam's stomach turned violently, a shudder running through him when he felt skin against his lips.
"You said yes," he breathed, voice heavy with want.
Hands clenched at his sides, nails digging into his palms, Sam slowly opened his mouth. The Devil breached him immediately, the thick head slimy with precum against Sam's tongue. His mouth was full of him, much too full. It was worse than just having a taste of some food you knew you wouldn't like. At least that could be gotten rid of, but this filled him up and then kept going till he was choking, eyes watering, hands up against Lucifer's hips to push him back. The Devil held onto one of his hands, trapping him there, and his other hand was slapping his cheek, as if that would somehow get him to relax.
"I'm sorry," Dean whispered, voice broken.
Sam imagined the tears streaming down his face. His fingers were trembling on his head, and Sam felt one of them - his ring finger on his right hand - move from his hair for a mere second. Panicked, he reached for his brother's wrist, not wanting to endure the agony of having some of his teeth pulled out. Sam was trapped between the two of them, one unwilling, the other more than, and in his wild panic, his struggle, he ended up opening his eyes. Through the blur of unshed tears he could see too much of the Devil's skin, and knew he wasn't in him all the way yet.
"Sammy, let go," Dean begged. "Listen to me, let go and hold your thumb against your palm."
He could feel himself gagging, all of him fighting this horrid invasion of his body. Sam didn't want to let go, wanted to hold his brother for some support, and to make sure he wouldn't release him. It didn't matter that he was about to be possessed - he needed his teeth.
Shaking, faint, and on the verge of throwing up, Sam let go of Dean's wrist, and tried to do what he told him. As if by some magic he felt his gag reflex relaxing, and he was too out of it to wonder how Dean knew such a thing.
"Okay, okay, now you gotta hum. Hum through it."
Sam couldn't seem to make himself do so, but then his nose was against Lucifer's pelvis, and he couldn't breathe, black spots taking over his vision, spit dribbling down his chin. He pulled his hips back, and Sam's first instinct was to bite, to bite and hurt, and just lie there and hope the bad thing went away. But he feared what would happen if he disobeyed, if he fought his possession before the proper time. He began to hum, his voice sounding strangled, lost to terror.
"You know, fuck you, Dean," Lucifer growled out, as he thrust forward. "I was really looking forward to properly ruining him first."
Even with Dean's advice Sam was struggling, Lucifer's hardened cock reaching too far into him. And he was cold, unnaturally cold, and Sam felt it gnawing at his lips.
Dean's fingers continued to shake, but he held him steady, even when Sam struggled, tried pulling his head back and away. And Lucifer grabbed at what he could - hair that wasn't trapped by Dean's fingers, his jaw, and then his neck. He was telling him that he owned him. A year of refusing him had led to this, led to this pent up anger and frustration that the Devil fucked into his mouth with. A year of waiting, a year of an I told you so that had to be said.
"You know, I don't suppose you'd just say yes here and now? End this whole tiresome discussion? That's crazy, right?"
"It's never gonna happen!"
"Oh, I don't know, Sam. I think it will. I think it'll happen soon. Within six months. And I think it'll happen in Detroit."
Six months to the day and Sam was on his knees before him in Detroit. Six months to the day and a yes had passed his lips. Sam had been playing this game for a year, but Lucifer had been playing since nearly time began, waiting for him, waiting for his perfect vessel to be born, to grow, to be filled with the blood of demons so that he could finally take him when the time was right.
That was made evident to Sam with every thrust of his hips. The emotions that Lucifer felt went beyond human comprehension, his every motion seared with his intent, his want, his need, his pure and utter satisfaction. This human act, this desecration, was underscored and throbbing with something far older than Sam, something with power he could barely begin to grasp, had hardly had a taste of, even with the way his mouth was filled. And Lucifer was not one to be quiet about this victory. He growled and moaned, voice surely loud enough to be heard by other demons he had in the abandoned building.
The floor was hard and cold against his legs, and his thumb ached from how tightly he grasped it against his palm. Sam had to let up, tried to steady himself, and what was an atrocious experience became ten times worse. Lucifer didn't show mercy as he choked and gagged on every inch of him, surely bruising his throat.
Finally, he pulled back, and Sam fell forward a few inches, sicking up on the floor. Blood. It was all blood. A foot was put under his chin and used to lift his head back up, and the Devil's hand grasped at his jaw, trying to pry his mouth open. The other was on his nose, stopping him from getting air in. With Sam still feeling as if he was going to throw up again and desperately needing air, he opened his mouth, only to be met with violation. Dean's hands never left him, fingers like iron on his head. He hated him. He loved him. It hurt, just as much as the shame that shot bullets into his sternum. Sam would never breathe the free air again, forever marked by this evil.
In some sick, vile way, Sam wished the situation were reversed, that he was Lucifer in this situation, and Lucifer was the victim. He had never thought he'd wish this upon another being, but he wanted to take all this discomfort and pain and trade them in for the pleasure his body was granting him with. This was Sam's first act in service to Lucifer, the first giving of himself to him.
After a certain point Sam grew bored. It wasn't that he was used to how he struggled for breath, struggled to have one moment of his body to himself, struggled to be free from the taste and feel of thick, hardened flesh that was slick with precum and saliva. He wasn't used to the way his eyes watered, the way his blood rushed through him so fiercely that the very presence of it pumping through him hurt, the way his head spun, the way he was manhandled by the Devil, and by his brother who was just following orders to save him. But it was relentless, and there was no escape, so in a way, Sam found one.
This wasn't happening. It was that simple. Reality was amorphous, a shimmering dimension obscured by layers of cloudy uncertainty. Sam felt as if at any moment now one action, one sound, one sensation, would be too much, and it would shatter, like a glass window. He tried to bash against that window, clawed at Lucifer's skin, heard and felt his voice leaving him, but the window disappeared.
This was happening.
Then, the window was back again, filthy and murky like scum over a stagnant pond. Sam feared that he was going to fall in, drown in its freezing darkness.
On and on it went like that, Sam trying to see through this reality into another where he was anywhere but here, and each time it eluded him, just out of sight, a color that he couldn't see, some light that was almost in his vision. But there was only this, and his whole body was hot and tingling, with sensation getting beaten into it.
After long moments of fighting - with himself, with Dean, with Lucifer - he tasted his defeat and ruination, finding it thick and burning cold against his tongue, a wet bitterness that he'd never wanted to taste.
"...you will say yes to me."
Then he felt him filling him up, trailing in through his mouth, into his throat, up through his sinuses…
"You're wrong."
...down into his lungs, down his esophagus into his stomach…
"I'm not. I think I know you better than you know yourself."
...through to his brain, his heart, his nervous system, his muscles, his bones…
"Why me?"
...till all of Sam was all of him: the Devil.
"Because it had to be you, Sam. It always had to be you."