For what had started out (somewhat) innocent, it turned into something illicit quickly. Even if Cas had sought Lucifer's touch more often than necessary, sneaking sniffs and holding hands, he had never thought he'd up her grinding his ass hard against his big brothers hard-on. Fantasizing was one thing, but actually doing it?
Ever since the first time last week, every night at two am, Cas would wander to the living room to find Lucifer sitting on the couch, legs spread wide. By the third time, Lucifer had stopped wearing his jeans; just waited for Cas wearing nothing but boxers.
Cas didn't even bother with pretence; he just sat right on his brother's dick, wearing nothing but his pyjama bottoms (hey, if Lucifer wasn't going to wear a shirt, than neither was he) and grind. Unlike the first time, Lucifer stuffed one large hand into Castiel's pyjamas, the other roaming across his bare chest, and stroke him until he came.
Castiel was young and it didn't take long, nor much stimulation, to have him shooting into his brothers rough palm. He would've been embarrassed if Lucifer didn't take advantage of that and make him come three times a night, before finally unloading all over his back.
Cas watched the green numbers on his alarm switch over to two before slipping out of bed. He and Lucifer had been forced to do their own laundry secretly due to their activities and so they were soft and fresh against his bare skin, smelling of fabric softener. He padded down the hallway and the stairs, the house pitch black save for the light from the television. Just hearing the tinny voices of whatever Lucifer was watching made his heart beat faster, the flickering light on the wall and ceiling exciting him so much he was starting to tingle already.
Lucifer leisurely rubbed at himself; not enough for it Castiel to consider it masturbating, but enough where he was wasn't entirely soft.
All Lucifer did was smirk as a greeting.
Instead of sitting between his legs, Castiel tried something new. He straddled, facing the television, back-to-chest. The cushions were soft beneath his shins, Lucifer's strong thighs warm against Castiel's inner legs. The cock pressed against his pants, still mostly soft. Cas' own dick was already stiff.
Cas rolled his hips and Lucifer moaned quietly. "Have I told you lately that you're my favourite sibling?" he asked quietly. His chest rumbled against Cas' back.
"You mentioned it yesterday," Cas muttered bluntly.
Lucifer nipped at his earlobe and press his palm over Castiel's erection. "You're sassy. I love it."
He rubbed him through his pants, other hand gripping his hip. Cas pressed against Lucifer's chest, toes curling and knees squeezing the thighs he surrounded. It wasn't until then Cas actually saw what was on the television, despite having been facing it the entire time.
Everyone knew about the late-night shows on Cinemax; soft core porn masquerading as erotic romantic movies. He'd never bothered to watch. He was still relatively new to touching himself, and had never ventured out of his own mind. Seeing a woman bounce eagerly on a man, moaning loudly (though with the volume as low as it was, Cas could hardly hear it over the beat of his heart in his chest) was hotter than he had thought it would be. Lucifer grasped him through his pants, stroking him hard, the cool fabric sliding over his dick.
"You like that, Cassy?" Cas tipped his head back and to the side, giving his brother's tongue access to his throat. "It's even better when you can see the cock going in. Watch his spunk spill out of her wet pussy."
"I imagine so," He said, hoping he sounded as husky as his brother, but he doubted it. Dirty talk was not his strong suit; not like Lucifer, anyway.
Lucifer chuckled and bit down on his throat. "I love your smooth little ass humping my dick more, though."
Cas groaned and his eyes shut. The sound of fabric sliding and their breaths overwhelmed him, Lucifer ducking on his neck gently and licking his ear, one hand rubbing small circles on his abdomen, the other finally sliding into his pants. Lucifer's hand was so warm and gripped him so perfectly, he nearly came at the first touch.
"Do you touch yourself, Cassy? Do you think about me fucking you over the kitchen table?" Cas whimpered, pinching his lips tightly closed. "I'll take that as a yes."
"I do," Cas answered belatedly and uselessly. "I think about you . . . putting it in me. And . . . coming inside of me." He would've felt stupid if he weren't on the edge of coming.
"Me too, baby. Think about how tight your virgin ass would be, slipping around my thick, hard cock. I'd make you scream, little brother. I'd fuck you so hard you wouldn't walk right for a week. You want my cum dripping out of your hole?"
Lucifer jerked him hard and humped against his back. He tipped over the edge, slowly yet quickly at the same time, and he let out a long, but hopefully quiet, groan. The burn in his belly spread to his legs and pelvis, ejaculate slicking up his shaft.
Lucifer pulled his hand free, pushing his dick faster against Cas' bum. Lucifer stuck his semen-covered finger into Castiel's mouth; or rather, Castiel sucked on it, tasting himself on his thick digits. He sucked, harder. He'd never tasted cum before and to be honest, it wasn't something he loved having on his tongue. If he weren't still coming down from his orgasm he probably would've pulled away but instead, he sucked on it; licked his digits while he humped downward.
"You don't even know how hot you are, baby. Such an innocent little slut, sucking your own cum off my hand. You like that huh? You like having your big brother jerk you off?"
Castiel licked his hands clean for a response, quickening the pace of his rolling hips. Lucifer's now-clean hand held Cas' small waist, guiding him faster and pushing his down harder. "You're so hot when you cum, Cassy. Wish I could have you on my dick twenty-four-fucking-seven God."
Wet warmth hit his back and soaked through his pants suddenly, Lucifer grunting and snapping his hips beneath him. Castiel finally opened his eyes slowly, Lucifer's dick slowly softening beneath him.
The problem was that Cas had started to harden up again.
Cas rolled his hips and Lucifer hissed. "Not yet, baby. Still sensitive. Have an idea though. Get off and face me."
Castiel stood from Lucifer's lap and turned around. His boxers were wet and covered in sticky white, soft cock poking out of the slit of his boxers. "C'mere." He slapped his knee with a smirk.
Cas obeyed and straddled his brother, hard penis straining against his pyjamas. Cas placed his hands on Lucifer's shoulders. Lucifer's chest was so much broader than his, his shoulders wide. Cas was thirteen but small for his age; wiry, even, and people had confused him for a girl before. He was so small against his twenty-eight year old brother, but he was so safe.
He remembered tucking into his chest when he was younger, or crawling into his bed after a bad nightmare, and this didn't feel too much different, although those innocent, familial touches from long ago now had a sexual undertone that Cas craved. He'd never felt like this before, with anyone; not just physically, but emotionally.
He leaned in, but Lucifer put his hands on Castiel's chest, stopping him. Before Cas could stutter out an apology, Lucifer smirked and slid his palms down his torso and the around to the small of his back. He grasped Cas' butt, hard. "Stand up."
"On the couch?"
"Don't be such a goody-goody," Lucifer scoffed, as if Cas hadn't rubbed his ass all over his cock ten seconds ago.
Cas stood up, wavering on the cushions. It was strange, being taller than his brother, but he could only marvel at it for a second, because Lucifer pushed his pyjama bottoms under his butt, free his little cock, and suck the entire length into his hot mouth.
Cas let out a drawn-out vowel, much louder than he should've, but he honestly couldn't help it. His cock plopped free from Lucifer's mouth. "Shh, Cas. You wanna get caught?"
He meant to apologise, but; "Suck it," came out instead in a low growl.
Lucifer grinned. "You're a bossy, slutty little shit. But be quiet about it."
Cas nodded, and Lucifer sucked on his cock again. The wet, slick heat of his mouth was the best thing Cas had ever felt in his life. His eyes watered from the pleasure and his knees buckled, already imbalanced on the couch. He buckled forward, hands clapping on the back of the couch to keep him in place.
He covered his mouth with his hand and thrust his hips into his brother's mouth, the pleasure building and building until-
He shouted into his palm, squeezing his eyes shut and coming so hard he forgot to breath. Usually when he came he breathed loud and rough, but now? Now he held his breath, slamming his cock as fast and hard as he could forward, tongue swirling around him.
He slumped to his knees, soft dick plopping out of his brother's mouth. He pressed his forehead to Lucifer's collarbone, finally gasping for air, body shaking.
"I got you, baby," Lucifer whispered against his hair.
Castiel burrowed into him, humming into his sweat-slicked skin. "I know."