Sam hadn’t thought things could get any better, honestly. Mainly because he was just too young to know how good things had the potential to get. It had been a year, almost, since the first time he’d convinced Dean to jerk him off. He had great memories of that, getting away with pretending he didn’t understand the whole process, or what to do, and whining to his brother to help me, Dean, please.
Dean might have figured out by now that Sam had been playing him that night, but it didn’t really matter anymore. Over the past year, they’d gone from stroking each other at night to grinding their cocks together until they came to that one perfect fucking moment when Dean finally kissed him, really kissed him for the first time.
That kiss, just that, was what made it real for Sam.
Two months ago, Dean had sucked his dick (for a minute and a half, because that’s all Sam could last before he shot right down his brother’s throat). Dean hadn’t teased him about it, though, and two weeks later he let Sam try it himself. Not an easy task, Dean was so big and Sam couldn’t get all that much of his cock into his mouth, but he figured it was enough because he made Dean come.
He did that. Young and inexperienced as he was, only a few weeks past his twelfth birthday, somehow, it was good enough to get Dean off and there was nothing in the world better than that, he knew, for sure, right at that moment.
But Sam had been wrong about that.
They’d been building up to this for the past few weeks, Dean slowly getting him used to the feeling of intrusion, one finger at a time probing his ass. And it was good, so damn good, he couldn’t wait until…well, until now.
Dean slid Sammy onto his lap once they were both naked and he’d spent some time lubing up his hole, spreading him open, getting him ready. Sam was still so fucking tiny, barely even had any hair around his dick or balls, and light enough that lifting him up and placing his legs against Dean’s own on the edge of the bed was no effort at all.
The fingering he’d already done hadn’t affected Sammy’s erection a bit; stiff little cock still standing up and hard against his belly.
One more time, he couldn’t help himself, he had to ask, just one more time.
“You sure, Sammy?”
The response he got in return was as much of a growl that a twelve year old kid could possibly muster, along with Sammy grinding against him as hard as he could and gritting out a “Y-yeah, yeah, please…”
All right then. Dean had given himself lots of time to get over his initial guilty feelings about what he did with his baby brother. Sam had initiated it, had been the one to push for more, every time.
Dean let out a deep exhale and positioned Sammy just right, then slid his lubed up cock into Sammy’s waiting hole. He was prepared for the tightness, for Sam’s grip around his shoulders, and he held himself still.
“Gonna go slow, okay? Real slow. I know it hurts. You tell me to stop and I’ll stop, I swear.”
“Fuck, Dean, no, please don’t stop, don’t stop, I want it so bad.”
Damn it, even with the words he was saying, his voice still sounded so damn young. And if it was fucked up that Dean was turned on by it, then fine, it was fucked up. Whatever.
Sam put all his effort into trying to relax all of his muscles. It hurt, honestly, it did, not the same as having fingers inside him. Dean’s dick was so big, but Sam wanted it, wanted every inch of it. So he steadied his breathing and concentrated on sinking himself down, down, farther down, until he felt himself flush with his brother’s lap.
How could it feel so goddamn good to be split wide open on Dean’s huge cock? For just a second, the thought crossed his mind that it would never feel this good for Dean if he ever let Sam fuck him, because he was still so small. The thought was chased away, though, when Dean started thrusting upwards, almost bouncing Sam up and down on his lap.
And then he heard it – Dean sighed, moaned and said, “Fuck, Sammy, feels so damn good, you’re so fucking tight, it’s perfect, you’re perfect.”
Sam’s heart and his ego and his dick all swelled at the same time. He was making Dean happy, he was giving Dean pleasure. He was good enough, somehow, impossibly, good enough to make Dean groan and pant, good enough that Dean’s eyes were rolling back and his face was a mask of lust and want.
He hadn’t thought it would be possible. Dean had been with girls before, had plenty of experience with sex, Sam figured anything he could give to his brother would be second-rate at best.
That was clearly not the case, though, as Dean’s movements became more uncontrolled, more erratic. Sam just reveled in how mind-blowingly fantastic it felt to be filled up like this, stuffed full of cock, and all of a sudden, he was coming, spilling all over himself and Dean without his dick even being touched, feeling dizzy and weak.
Another minute, maybe not even that long, and Dean’s grip on him grew tighter as he felt Dean fill up his ass with his own cum.
Sam was weak and still reeling from his own orgasm when he felt Dean kiss the top of his head. He knew at some point he was going to have to slide off Dean’s lap, but for just this very minute, he held on with everything he had.