Dean had always been into the more "spicy" side of sex; wearing panties, using handcuffs, hell even getting spanked with a riding crop occasionally - it all turned him on. But he had never known what a kinky motherfucker he really was until this very moment.

He was on his knees in the bunker library, wearing a collar, leash, puppy mask, and puppy paw gloves, sitting back on his haunches and begging Sam for a treat; he had never felt more aroused. Honestly, he wasn't entirely sure if it was the praise aspect of it or if he really just craved being taken care of and having his decisions made for him. He supposed it was all of it...and seeing how hard Sam got watching Dean put on the costume didn't hurt either.

"Does puppy want another treat?" Sam asked, giving the bulge in his jeans a little squeeze as he stood before Dean.

Dean sat up straighter and gave Sam a happy bark, even sticking his tongue out of the mouth opening in his mask. Sam smiled and tossed Dean a piece of a cracker. The first piece he had tossed Dean only moments before had bounced off his nose and landed on the floor. Sam had made Dean eat it off the hardwood, which Dean had done with no complaints. This time though, he caught the treat in his mouth.

"Good boy!" Sam exclaimed, reaching forward to pat Dean on the head.

Dean's heart and cock swelled with the praise and he went down on all fours to accept Sam's pets. Sam's hand moved back to scritch behind Dean's ear and Dean took the opportunity to give Sam's arm a playful lick.

Sam shivered visibly from the contact and Dean wriggled his hips from side to side, making the tail-plug in his asshole wag back and forth. The plug was sticking out through a hole cut into Dean's briefs and the feeling of the slightly weighted toy moving inside him sent a warm stripe of pleasure throbbing through his whole body.

He had to work very hard to bite back the groan bubbling up in his throat. Sam had already told him that if he followed the rules and only made puppy noises that he'd be rewarded, and damn did Dean want that reward. Just the prospect of Sam's thick cock filling him was almost enough to send Dean over the edge. But he didn't dare come until Sam gave him permission.

Sam grinned knowingly at Dean then scooped up the leash hanging from Dean's neck before straightening. He began walking back toward the bedrooms and commanded Dean to "Heel!"

Dean followed along immediately, shuffling beside Sam on his hands and knees. The excitement coiled tighter and tighter in Dean's belly the closer they got to their shared room. Anticipation was flushing through him with each pounding beat of his heart as they crossed over the threshold and his eager hole clenched around his tail-plug. He couldn't help the whine that escaped his lips; his body was crying out to be filled by Sam in every way possible.

Sam chuckled softly and led Dean to the bed. "You've been such a good boy. I think it's time for your reward," he said, patting the bed.

Dean let out a little yip and scrambled up onto the bed. Sam guided him to lay his head down on the bed and keep his ass up in the air. His brother's large warm hands were suddenly on Dean's ass cheeks,kneading them and spreading them apart. The toy was jostled with the movements and brushed teasingly over his throbbing prostate and Dean began to tremble all over.

Another whine fell from his lips and Sam immediately shushed him. "Now, now, pup, I'll give you what you earned. Trust me."

The sound of a zip fly being pulled slowly down its tracks nearly had Dean's eyes rolling back in his head. He couldn't take much more. The shuffling of clothes behind him signified that he hopefully wouldn't have to wait much longer.

And then Sam's hands were on him again, gently pulling his briefs down. He took care to pull Dean's tail from the underwear without pulling the plug from his body. As soon as the material, wet from the copious amount of precome he leaked into them, were pushed down to his knees, Dean was on the very verge of falling apart.

The feeling of the plug moving suddenly caught his attention. Sam was pushing it back and forth and pulling it out halfway then pushing it back in. Dean was about to lose his mind.

"I'm going to pull this out now but I'm going to replace it with my cock since you've been such a good boy for me."

Dean whimpered and felt Sam drape himself over his back. Sam's breath was hot and humid in his ear as he whispered, "And as soon as I'm done filling that asshole with my come I'm going to put this plug back in so you can sleep all night with a part of me inside you like the good boy you are."

Sam quickly made good on his promise before Dean had a chance to squeak out any noises at all. The toy was tugged from his hole with a wet suction and he felt his lax ring of muscle try to tighten over nothing for a moment before Sam was shoving his massive cock inside him.

Dean yelped, pawing at the covers beneath him when Sam bottomed out fully on that first initial thrust. The weight of Sam's dick always filled him so perfect, but right now, in this moment with his arousal keyed up higher than it had ever been, it felt like absolute fucking bliss.

Sam began drawing out then stroking back in with a rhythm that was pushing Dean closer and closer to orgasm. His cock was rock-hard where it swung heavy between his legs, but with the puppy gloves on he couldn't even hope to be able to jerk it himself. He tried anyways, reaching a hand beneath him to press at his dick, to try to relieve just some of the pressure building there.

Sam immediately stopped moving behind him and pulled Dean's arm back out from under him. "Ah,ah,ah,puppy," he admonished, "You're not supposed to come until I say, remember?"

Dean growled desperately, his control cracking, "Goddammit, Sam, C'mon! I'm hard enough to cut fuckin diamonds here!"

The thick weight of Sam's dick was pulled from Dean's body with a sudden aching rush. "You're being a very bad dog," Sam said in a warning tone. "I'll give you one more chance to follow the instructions or else you don't get your reward."

Dean swallowed hard and closed his eyes. He felt like if Sam didn't let him come soon, he might just keel over and die. Rolling over onto his back, Dean let out a low, needy whine, showing his belly submissively. Sam smiled at Dean's wordless apology and knelt on the bed to rub Dean's flushed tummy.

Dean's hard, leaking cock jerked with the touch, causing a long shiny string of precome to be caught in his curly pubic hair. Sam's eyes traced over every inch of Dean's body with an undeniable hunger before grabbing Dean's ankles and shoving them up over his broad shoulders.

And then he finally, finally pushed back inside Dean. Dean's greedy hole accepted him eagerly, sucking Sam in as deep as he would go. Dean wasn't sure in that moment if puppies could moan but he didn't want to risk this last chance Sam had given him so he bit the inside of his cheek hard enough to draw blood to stifle the pleasurable sound.

It wasn't long before they were both slicked with sweat and Sam's soaked bangs were hanging down into his eyes, bouncing wildly with each thrust into Dean's ass. Dean's cock continued leaking down onto his belly with each pass of Sam's dick over his prostate, leaving a sticky pool all over his skin.

Dean had never come without his cock being touched at least once, but he was pretty sure he'd have no problem shooting his load completely untouched tonight. His body was more than ready, tightened up and hyperaware. He felt like he could feel every vein and hard ridge of Sam's dick as it plowed into him, could feel how his insides moved to accommodate the wide girth of that member. Christ, he was so fucking close.

Just then, as if reading his damn mind, Sam leaned forward, digging his knees info the mattress and almost bending Dean in half. "It's time for my good boy to get his reward," Sam said hoarsely, his flushed face inches from Dean's puppy mask. "Come for me. Come right fucking now."

Dean felt Sam press in as deep as he could go, the blunt head of his cock jabbing right into the hard knot of his prostate and Dean saw stars, he swore he did. He followed Sam's command immediately, howling out with the force of his orgasm, and spurting come out of his spasming dick all up his stomach and chest.

"Good boy, good boy," Sam chanted through gritted teeth,pumping his hips forward one last time before spilling his release hotly inside Dean.

Dean's heart soared with Sam's praise and the warm afterglow suffusing through all his nerve endings. He panted for breath as Sam pulled out gingerly then felt it hitch in his chest when Sam slid his tail-plug back in before any come could escape from his tender and gaping hole.

Sam then took off all the other pieces of Dean's puppy costume, starting with the the collar and leash and finishing with the mask. Dean breathed deep when the cool air in the bedroom hit his sweaty face. Sam smiled at him gently and pressed a soft kiss to Dean's lips before guiding him to lay on his side. He curled up along Dean's back and wrapped Dean in his arms, smoothing his hand through Dean's sweat-stiff hair.

"Good boy," Sam whispered, huddling Dean close to his chest. "You did so good."

Dean drifted off to sleep with a smile on his face and Sam's spend locked warmly inside him, more sated and content than he could ever remember feeling before.