A/N: Takes place during season seven of Supernatural where Sam has his hallucinations of Lucifer and Dean causes him pain to make Sam realize what is real. This is a very… kinky version of what could have happened. Might be established relationship, I don't know. You tell me.
WARNINGS FOR BONDAGE, BLOODPLAY, KNIVES, AND INTENTIONALLY CAUSING PAIN. This really isn't for sensitive readers.
Pain was the only thing that worked; that kept him sane. And so when Dean suggested an unusual form of treatment, Sam, stunned and terrified, shook his head in a tiny "yes."
Dean swallowed hard, composing himself. At once, he lunged, pinning Sam against the wall. His younger brother's head snapped back and slammed into the drywall. Sam grunted, vision swimming. Lucifer watched in the corner, saying nothing, a smirk on his face. Dean's hand met Sam's throat.
"Dean?" Sam asked. Dean's eyes were determined.
"Trust me," he said, and Sam nodded. Using the hand on Sam's throat, Dean forced Sam's head back against the wall and bit at his neck. It hurt; hurt like hell. But Sam couldn't help but let out a groan.
Dean's eyebrows shot up, the ghost of a smirk on his face. Sam's eyes flicked over to Lucifer, watching the two with a measured glance. Dean noticed and bit down harder, tiny, painful nips, moving down to Sam's shoulder with more blunt, open-mouthed bites. Sam's mind twisted with the pleasure/pain of it, and Lucifer sitting in the corner began to fade.
"Is this helping?" Dean asked, pulling his mouth away from Sam's neck. Sam's pupils were blown wide.
"Do it again," Sam commanded. Dean peppered Sam's skin with little bites, dark hickeys, at times biting so hard that he began to taste blood. His nails started digging into Sam's skin.
Sam hissed in anticipation as the little bites disappeared, hips bucking forward as Dean inspected him curiously. Dean licked a wide stripe up the side of Sam's bleeding neck, breath whispering against his skin.
"How far do you want to go?"
Sam's eyes closed as he admitted: "More."
Dean stripped off the heavy jacket he was wearing, draping it over a chair, then grabbed something off the adjacent desk. Sam couldn't see what it was until Dean tightly grabbed one of his wrists. He roughly tied a knot around Sam's wrist with the coil of rope, then forced Sam down on to the bed on his knees, tying his other wrist close to the first around the bedpost, leaving Sam unable to move his arms.
"Those hurt enough?" Dean asked.
"Dean, I need more," Sam growled.
"Don't worry, Sammy," Dean practically purred. "Gonna give you more. That's just to keep you still."
Sam swallowed hard. He felt his flannel being pushed up, exposing his back. Dean licked his lips. Sam realized he was holding a serrated knife in one hand.
"Dean, do it," Sam commanded, pushing back into Dean's body, kneeling beside him on the bed. Dean made a cautious cut, each of the individual points of the blade sawing into Sam's flesh.
Sam's head snapped back and he screamed, so loud that Dean pulled the knife away immediately. He didn't move until Sam turned back to look at him.
"Dean, I need it." Sam met his gaze, panting. "Please."
Dean cut again, shallower, and Sam whimpered, a release of tension instead of an exclamation of pain. Dean sensed this and the next cut immediately followed. Blood spilled from the wounds and dripped down to the sheets as Sam arched back into the blade, pulling back on the coils binding his hands, rope digging into his wrists.
Dean sawed one last cut into Sam's skin, pulling the knife away entirely. Sam tried to follow the movement by arching his back, whimpering as he did so.
"Dean, I need more."
"Sammy, I don't want to—" He left the phrase unspoken, a grimace on his face. Kill you.
"Dean, you gotta think of something. Hurry."
Dean cursed and thought fast, the only thing coming to mind being—
"Sam. Trust me."
Dean quickly stripped Sam of his pants, darting underneath his brother's spread legs and to his cock, scraping the underside with his teeth as he placed a shallow cut on his hip. Sam jumped and pushed back so hard that one of his hands was jerked free of the rope.
"Is this—" Dean was quieted as Sam used his free hand to push Dean back down.
Dean wrapped his lips around the head and sucked, hollowing his cheeks, feeling Sam jolt. Neither one was fully hard yet, but Sam was well on his way, unable to help himself at the feel of Dean's mouth.
Sam was gasping, body shaking at the sensations. His hips bucked again, pushing his cock deeper into Dean's mouth. Dean growled, mouth vibrating. Sam groaned.
Dean put his hands on Sam's shoulders and flipped him over. Sam growled as the white sheets pulled on his still fresh cuts and his arm was twisted in a strange angle, still tied to the bedpost.
"Please," Sam begged, "Dean." He blushed, averting his gaze. "Fuck me."
Dean didn't bat an eyelash, just rolled over and stretched his arm out to the nightstand, pulling out a tube of lube. Sam reached out, touched Dean's hand.
"Dean. I don't need it." Sam took his brother's hand and sucked on Dean's fingers, coating them with saliva. Sam sat back, releasing Dean's fingers from his mouth with an obscene noise. Dean worked two fingers inside of Sam, reveling at how tight he was. Sam groaned at the stretch, just enough saliva to keep the sensation from being uncomfortable, but not too much as to take away the needed pain.
Dean stretched and prepped Sam until his younger brother was squirming underneath his touch, locking eyes with Dean. Dean unbuttoned his pants and Sam reached out desperately, taking Dean into his mouth and lavishing his cock with the same attention that he gave his fingers. Sam spread his legs further and Dean pushed inside Sam, tight skin pulling in a way that make Sam groan. Dean immediately pulled out and pushed back in, keeping Sam boarding on the edge of pleasure and pain, making him squirm and cry out.
Dean had set a punishing pace, but Sam matched it, and before long, they were screaming their release together, Sam wincing as his come mingled in his wounds, and Dean spilling deep inside Sam.
"Was that okay?" Dean asked him. "Are the hallucinations gone?"
Sam nodded seriously, completely spent. "Yeah," he answered. "For now, anyway."