Dean couldn’t help but notice how much of a brat Sam had been after school. Sure, Sam had his moments, but it felt like he was suddenly making sure to hit all of Dean’s buttons. Coming home late, talking back, it was a lot for Dean to handle on his own.
Their dad was gone on a hunt, which meant Dean was in charge of Sam, of course. It was so much easier when Sam was younger and looked up to Dean. Something changed in the last year when Sam turned sixteen, he was spiteful every chance he got.
Finally, Dean had enough.
“Sam, what the hell is wrong with you lately?” Dean asked once Friday afternoon when Sam was being particularly shitty. The young man scoffed and shook his head.
“Nothing, Dean. Now fuck off.” Sam grumbled as he pulled his homework from his bag. Dean felt rage boil inside of him as he stood up and neared his little brother.
“Do not talk to me that way, Sam. It’s disrespectful.” Dean ground out. His nails dug into his palm as Sam laughed at that.
“What are you going to do? Spank me?”
It was like a lightbulb went off in Dean’s head. Of course, it was time for discipline. Dean stood tall over him, his eyes dark. And for a moment, he saw true fear flash over Sam’s features.
“Get up. Now, Sam.” Dean ground out. Sam visibly gulped at that but surprisingly did not argue as he made the short walk from the motel’s table to the bed closest to the wall.
Dean couldn’t help but find it odd that his brother wasn’t fighting him about it, but he couldn’t back down then. Sam needed to be taught a lesson.
Dean made his way over to his soundless brother and sat on the bed. Wordlessly, Sam draped himself over Dean’s lap. Soon after, Dean pulled Sam’s pants down to the middle of his thighs, so just his underwear was showing. Sam gripped the sheets in what Dean assumed to be was fear for what was to come.
The first strike was loud, but so was Sam’s gasp. Dean didn’t think much of it as the second one echoed through the room. And then another, and another, harder each time. Sam’s sounds didn’t let up.
Dean was confused. Sam didn’t sound like that when their father spanked him. In fact, he didn’t make a sound at all until it was over and he was silently crying to himself in the bathroom in whatever motel room they were in that day.
Dean pushed the thought away. He kept the same pace but on the other cheek, and without really meaning to slapped right on his thigh, on his bare skin. That made Sam’s noises turn from slight gasps to an outright moan.
That made Dean’s movements stop abruptly.
“Dean, please. I promise I’ll be good. Just… don’t stop.” Sam let out, his tone utterly breathless. And Dean knew full well that he should have stopped. He should have walked away from the situation so he clear his head and talk to Sam later about how fucked up that was.
But something in Dean snapped. There was a part of him that he had tried his best to keep buried, but it felt as though there was nothing he could do to stop himself in that moment. His hand raised and made contact with Sam’s underwear covered ass once more, but that time he made sure to grip Sam’s plumb little bottom.
“De,” Sam moaned as he rutted against his big brother’s lap. Dean cursed under his breath, his hand seemingly moving in its own as he pulled the younger man’s underwear down. His ass was red already, but Sam was begging for more. Dean obliged.
The pace of Dean’s strikes changed slightly. Harder, a little faster, his brain transfixed on the way Sam’s ass would jiggle slightly, barely registering the stinging in his palm. Sam made sure to ground down on Dean’s lap after each slap, just a few centimeters away from Dean’s own erection. But Dean didn’t care about his own release, not right then.
When Sam’s ass was a dark red that looked just about ready to bruise, Dean’s strikes softened, much to Sam’s dismay. But it turned into him pulling those cheeks apart, his own groan sounding almost like a growl as he finally laid eyes on that tight little pucker.
Sam’s sounds of disappointment turned into pure excitement after that. “Yes, De, please. Touch me. Want you in me.” Sam arched his back slightly, showing off just a little bit more, as though Dean needed more convincing.
Dean spit right down onto the little hole and circled a single finger around the entrance. After a couple teasing spanks to the opening, Dean finally breached through.
“Dean!” Sam yelped, and Dean moaned under his breath as he felt those tight walls around his finger. He couldn’t help but wonder how it would feel around his cock. How it’d feel to have Sammy pressed against the mattress, cock filling him to the brim. Sam begging, crying, for more.
“Fuck, Sammy,” Dean breathed as he watched as his finger moved in and out, entranced by the way it looked as though Sam was sucking him in. Like his body was born for it. Born to be fucked by Dean.
“More, Dean. Please.” Sam begged, and Dean didn’t need to be asked twice. Two fingers were in Sam, and the younger boy was bucking his hips back into them. Dean scissored his fingers and he knew by Sam’s loud, broken moans that he had found his prostate.
It was as though Sam couldn’t form words, because if he could, he surely didn’t use them to let Dean know that he was coming. All he could do was hump erratically against his big brother’s thigh, his cum covering Dean’s pants.
Dean let Sam ride out his orgasm, but the moment Sam finally stilled, boneless across his lap, he removed his fingers. Sam whimpered slightly at the loss but it was a weak sound, like he didn’t have the energy to beg for more.
The older Winchester was reeling. He couldn’t believe he had done that. Dean got up from the bed with some complaint from Sam that he tried his best to ignore and went to the bathroom.
One look at his reflection scared him. His eyes were dark, his cheeks flushed. He was still so hard that it hurt. The guilt he had was slowly taking over any desire he had, however. This was his little brother for God’s sake.
And when he heard Sam knock on the bathroom door, he wasn’t sure if he should open the door at all. But as his feet moved, he knew there would be no point it fighting it. What ever was going to happen when he opened that door was going to happen regardless.
With a deep breath, Dean finally opened the door.