Chapter Text
It wasn't always like this. There used to be a time where all of it was new, when Dean's touch felt taboo, uncomfortable and wrong and yet shamefully good. Part of it was his father, no doubt. Dean was always too impulsive to hamper down the lust that bubbled to the surface whenever Cas was close to him. But there was a part of him that wanted it even then.
It started when he was three, after taking a bath and streaking through the house while his daddy shouted "Come back here, you little devil!" as he chased after him. He didn't really know what his cock was until then, not until his daddy scooped him up and said "At least cover up your bits before you run crazy, kid."
Cas had looked down at his bits then, just a little turtle head burrowed into wrinkled flesh, and wondered why he had to cover up when it was just the two of them in the house.
After that, it was second nature to look at his bit—that's what he called it in his head at the time, his bit—and touch it and move it, even hit it sometimes to see what happened.
It wasn't until later that he saw his daddy's. It wasn't like his at all. His was a bit, but Daddy's was more than a bit. It was a big—very big. Long and heavy, It looked like it would hurt to walk around with something like that between his legs, and Castiel was curious. Just like he did his own, he wanted to poke and prod his daddy's big. It wouldn't be the same as his, Cas knew. It looked soft and smooth, but not as squishy as his own.
But even that little—he was five by that time—he knew that thoughts like that were bad. No one was supposed to touch his bit, and he couldn't touch anyone else's either, not even if he was curious. He would get in trouble like that one time he pulled Suzie Miller's pigtails after she knocked his block tower before recess.
It was a Bad Thing, and it would get him in a lot of trouble with his daddy. Daddy would probably spank him, pull his pants right down below his bottom and spend the time making it real pink, and when he did, Cas wouldn't be able to help rubbing his bit against Daddy's thigh while he begged him to stop, cried that he wouldn't do it again, that he was sorry.
Thinking back on it, Cas was sure that he full-heartedly meant the apology, but not for the reasons his daddy had thought. The shame he felt over his daddy's knee came from the pleasure he took in it. Sitting on a sore bottom told him that Daddy wanted Castiel to think about him. Seeing how pink it was showed him that Daddy cared how he acted, that he wanted Cas to be a good boy.
Castiel wanted nothing more than to be Daddy's good boy.
"Such a good boy," Daddy would tell him when he put his dishes in the sink.
"Good boy," Daddy would say when he picked up all of his toys.
"My good boy," Daddy would praise when he brought home good grades in school.
But Cas’ daddy had two good boys, and Castiel was more than a little jealous that he wasn't the only one.
"So good for me, Sammy," Daddy would call out whenever his uncle stayed the night.
He'd seen Uncle Sammy kiss his daddy on the mouth, lick his daddy's big, smile when Daddy called him a good boy, good Sammy, and Cas wanted that too.
When it happened, it was nothing like he imagined. It was good, so good, but it hurt and it was wrong and it wasn't supposed to be good like it was. It was supposed to be a Bad Thing, and it was hard to wrap his mind around the fact that it was alright to like it, alright to want Daddy's hands all over him, alright to want to be tied down and taken hard and fast while Sammy sat plugged and writhing beside him.
It took a long time, before he understood that it was okay to want his daddy like that. Years really. Almost a decade now, and Cas was finally realizing that he didn’t need the excuse anymore, didn’t need to pretend to buy into the whole “taking medicine” scheme so that he could have his father like he’d always wanted.
"What are you thinking about, kiddo?"
Cas grinned. "Give you one guess."
"Nuh-uh. None of that.”
Cas pouted.
“You're insatiable, kid."
"And whose fault is that?"
Dean groaned. "Why is everything always my fault?"
"Let's see..." Cas shifted his hips up to brush his bare cock against his daddy's thigh. "Who's the one that decided to turn his prepubescent son into a sex kitten?"
Dean's breath hitched, and Cas grinned.
"And who's the one that invited Uncle Sammy along to help train me?"
He skimmed his fingers down his daddy's spine to grope his ass.
"And who's the one that sent me to school every single day filled with Daddy's medicine?"
"Nggh."
"Hmm?" Cas gripped Dean's cock in his hand and stroked it leisurely.
"Me. Fuck. It was… oh god… me."
"See?" Cas smirked. "Your fault."
And then Cas leaned down and took his daddy's cock in his mouth. It was warm and heavy on his tongue, wet because Cas's mouth was watering, but smooth and soft like always. It was the only part of his daddy's body that was soft to the touch.
Rough hands threaded through his hair to hold him deeper. This was always his favorite part, and daddy didn’t disappoint. Cas registered pain for a moment when the clutch of his hair tightened. And then Cas was choking, trying not to gag when his daddy's cock opened his throat. Spit pooled around the sides of his mouth to dribble down his chin. He was rock hard, cock dripping precome onto his thigh.
He was in heaven.
He could come just like this—would in fact, if he weren’t careful. His skin buzzed from the strength he could feel in Dean's grip. His mouth went slack and his throat opened up, letting Dean's cock deeper inside of him. Every bob of his head made his cock twitch another spurt of precome.
"So good, Cas. My good boy."
There they were. The magic words.
Cas pinched Dean's thigh, and Dean pulled out of his mouth. A single string of spit connected them for a moment until Dean hauled him up and sealed their mouths together. Strong arms came around him, and Cas lifted his legs up to circle his daddy's waist, arms wrapping around Dean's neck.
Cas broke their kiss to whisper in Dean's ear. "I'm ready, Daddy. Please."
Dean's cock hovered beneath his hole, and Cas could feel it, the phantom tingling of anticipation that made the hair on his neck stand straight up.
"Need it. Fuck. Need it in me now, Daddy.”
"I've got you, angel."
Cas choked on a breath when Dean's cock breached his hole.
Strong hands gripped his hips and pulled him down, flush with Dean's pelvis. The sudden fullness made Cas cry out, but he needed more.
Dean seemed to understand. Two steps and Cas' back pressed against a wall. Dean's hands came up under his thighs to hold him open as his thrusts turned wild, frantic.
Dean pressed their foreheads together and looked deep into Cas' eyes.
"I've got you," he said. "I've got you."
Cas knew he did, trusted his daddy implicitly.
"Go ahead, angel. Let go. I've got you."
Cas came hard, and he clenched down on his daddy's cock, feeling every inch of it inside him as Dean thrusted deeper, harder just like he liked it. Come dribbled down his cock between them, and he went slack in Dean's arms, let his daddy support him against the wall, take control of everything.
It was freeing like nothing else. He didn’t have to worry about anything when he was like this. Dean always took care of him.
His eyelids drooped closed even as he shivered with his daddy’s come filling him up. He was too relaxed and loose to keep it inside of him when Dean pulled out of him. Some of it dribbled onto the floor before they made it to the bed and Daddy could fit a plug inside of him.
A warm cloth wiped him down, and then he was pressed up against an equally warm body, soaking in the afterglow.
It hadn’t always been like this. He was the big spoon now, even though he was still a little smaller than his daddy. It wasn’t always Dean taking care of him like it had been when he was young. Now, it was something they both liked, taking care of each other.
"Never did tell me what you were really thinking about, kiddo," Dean whispered against his chest.
Cas smiled and kissed his daddy's greying temple. "Just us, how we started," he answered.
Dean chuckled. "We could go back to that if you'd like—me pretending to give you your medicine, you pretending you didn't want it, taking your medicine everyday to keep you strong and healthy."
Cas thought about it for a minute before he shook his head. "Nah. I think I like it better like this."
"Good." Dean kissed his neck.
"Though, I wouldn't mind another visit with Uncle Sammy. It's been awhile since I've been... filled."
Dean groaned. "God yes," he said.
But both of them were much too spent to mean it at the moment.
Later, they'll enjoy having Sam with them, both in their bed and out. For now, though, they're content to simply enjoy the moment, soaking in sweet kisses and loving touches, nothing but the two of them in the world.