Chapter Text
"So," said Dean, "anything else on your list of things to explore, you kinky fuck?" Cas bit his lip, considering. "Especially as our brothers are temporarily out of hearing distance," he added.
"Would... would you hit me?" Cas finally said. Dean raised an eyebrow. "The dichotomy of pleasure and pain has existed throughout all of human history. I've observed it for millenia, but have never had occasion to experience it."
"You want me to spank you?" Dean said.
Cas nodded and blushed. "Like the babysitter," he confirmed with a small smile.
Dean swallowed. "Yeah," he said. "We can do that."
He wasn't exactly shocked, really. He'd noticed Cas' reaction to that particular video (if by noticed one meant jerked off to it so hard his dick felt bruised), though based on Cas' previous request he would have guessed he'd be on the receiving end. Not that he was complaining.
"We're gonna have to lay out some ground rules, though," he said. "Like... do you just want me to slap your ass when I'm fucking you? Like you did to me? Or do you want me to lay you out and spank you raw, 'til you're screaming?"
Cas' blush intensified and he stared at his hands, but didn't reply. Dean put a finger under his chin and lifted his face to meet his eyes.
"From your silence, I'm gonna guess the latter," he said. Cas held his gaze for a moment, then looked away with a tiny, almost imperceptible nod. Dean smiled.
"You pick the strangest times to get shy, little angel," he whispered. "Sure weren't shy when you asked to tie me up. Bit different when you're on the other side, huh?" Cas nodded. Dean pinched his lower lip between his thumb and forefinger and tugged lightly. "And in front of my little brother, too," he added. "Pretty rude, really, when you know how hard Sam's trying to not freak out about us."
"I'm sorry," Cas managed. "I didn't mean --" Dean pulled harder on his lip and he shut up.
"And you get so bossy," he continued. "Like I'm in your garrison, under your command. Is that what you think?"
"N-no, Dean, you know I --" Dean cut him off with a kiss, wet and biting.
"What I know," he said, "is that you have some very bad habits. And some lessons to learn about humans." He slid his hand down Cas' back, then slapped his ass once, sharply. He knew it wouldn't really hurt, not through the jeans Cas was still wearing, but he heard the angel's breathing hitch, and he smiled.
"You like that?" he murmured. Cas bit back a moan, and was rewarded by two more slaps in quick succession.
Dean felt Cas hardening against his hip, and he reached down to press the heel of his hand against him through his jeans.
"Yeah, you do," he said, squeezing gently. "Hmm... You're not supposed to like it, Cas. Maybe I should stop. Should I stop?"
"No, please," Cas whispered.
Dean lowered his mouth to Cas' neck and bit down, then sucked hard at the same spot, and he could feel Cas' cock jerking against his own.
"Tell you what," he said into Castiel's ear. "I'm going to strip you naked, and throw you down on the bed. Then I am going to spank your ass until it is red and sore and hot, and so very tender. Until you're writhing on the bed, begging me to stop. And then, if you're very, very good, if you take it like a good little angel, I'm going to bend you over and fuck you, my hips slamming into your poor abused skin. Do you want that?"
Cas' breath was high and shallow, and he was trembling. Dean pulled back slightly.
"Hey," he said, brushing his thumb over Cas' lips. "You OK?" he asked, and Cas nodded. "You want a safeword?"
Cas cocked his head in confusion, and something in Dean melted, at how even like this, rock-hard and shaking with desire, there was so much innocence in the gesture.
"Um," he said. "It's a word we could assign so that if you say it, I'll stop immediately, I'll know it's too much. Because, Cas, I gotta tell you, I intend to break you apart, and don't expect me to go easy on you."
Cas thought about this for a few moments, then shook his head. "No," he said. "You'd know. I trust you."
Dean smiled at this, then kissed him soft and tender. He undressed Cas slowly, worshipfully. His hands played over his back as he slipped the shirt off, and as he knelt to tug off his jeans, he rubbed his cheek over Cas’ cock.
Finally he stood up. “Love you,” he said against his lips, running soothing hands over his skin.
“Dean,” Cas whispered, and Dean smiled.
Without warning he flipped Cas around and shoved him onto the bed. Cas jerked in surprise, and tried to crawl up on his knees, but Dean was on him, straddling the back of his thighs.
“Are -- are you going to get undressed?” Cas asked shakily.
“Would it make you more comfortable?”
“I’d feel less -- less vulnerable,” Cas admitted.
“Then no,” Dean said simply.
He ran his fingertips over Castiel’s skin, tracing lines between the freckles scattered across his back.
“Do you have any idea how gorgeous you are?” he asked, sincerely. Cas only groaned, and Dean smacked him once, hard. The first hint of pink began to appear on his perfect pale skin. “I asked you a question,” Dean growled.
“No,” he gasped. “N-no. Only --”
“Only what, Cas?”
“Only when you touch me,” Cas whispered, and Dean had to reach down and palm himself through his jeans.
“Your skin’s so beautiful,” he murmured. “So fine, so smooth. Fuck, I can’t wait to see what it looks like all marked up.” He leaned down and bit Cas’ ass, hard enough to leave imprints of his teeth, then rubbed his thumb over the marks. Cas jerked underneath him.
Dean smacked him again, on the other side. “Gonna have to hold still,” he said. “I could tie you up, I suppose -- God, you’d look amazing like that, spread-eagled and tied down to the bed. Another time, though.” He spanked Cas three times in the same spot, and Cas moaned.
“I love the sounds you make,” Dean whispered. “Good thing Sam and Gabe went out, because I want to drag sounds out of you that you never knew were in you. You know I’d still do it if they were there, though, right on the other side of the wall, and could hear everything. Hear you, Castiel, angel of the Lord, getting spanked like a naughty little boy,” and he dropped two more sharp blows, like punctuation, “and fucking loving it. Aren’t you, little angel?” He slipped a hand under Cas’ hips and found his cock pulsingly hard and fucking dripping. He swiped over the head, gathering liquid on his fingers, then dragged his wet fingers down Cas’ spine.
“Yeah, you are,” he said. “God, you’re close already, aren’t you? You know I’m not stopping if you come too soon.” He slid his fingers lower, spreading him open slightly and teasing him. Cas let out a sob and tried to push back.
Dean laughed and pulled away. “Not even close,” he said. “How did you phrase it? -- ‘You’ll take what I give you, or I won’t give you anything at all’?”
He dropped a gentle kiss at the base of Cas’ spine and ran his hands over his ass. The skin was warm but not hot, and while his breathing was ragged, he didn’t flinch at the touch.
“Good boy,” he murmured, and smacked at the juncture of Cas’ ass with his legs several times, alternating sides. Cas choked and whined.
“Yeah,” Dean said, kneading the tender skin gently, “gonna be sore tomorrow. Every time you sit down, I’ll see you flinch, and you’ll know I’m picturing you like this. ’Course you could heal it, but you won’t, will you?”
He waited, but no sound came from Cas except shallow breathing and small sobs from the back of his throat. He sighed loudly and leaned down.
“Shouldn’t have to teach an angel of the Lord to answer simple questions,” he whispered. “Even we humans know that.” He began to spank Cas in earnest, not too hard but not too fucking soft either. He leaned in to listen to the sounds Cas was making, so he’d know when it was time to give a reprieve, but fuck, it was hard to focus on anything but Castiel’s ass and his own dick.
“Dean,” Cas finally cried, “Dean, please, I -- I can’t take it, I --”
“Yes you can,” Dean said matter-of-factly, delivering one more stinging slap, but then he slid his hands over all of Cas’ body he could reach, pressing soothing touches into his back, but just slipping his fingers over the tormented skin beneath him, following with his lips and tongue, until Cas’ breathing settled down.
“Hey,” Dean said, stroking his ribs, “you OK? You want to stop?”
Cas drew in a great shuddering breath. “No,” he whispered. “Not yet.”
This time it was Dean who let out a groan. “The things you do to me,” he ground out. “Feel like I’m gonna come in my jeans.” He leaned down and spread Cas open again, pressing his tongue up against him, while squeezing his tender flesh in his hands. Cas bucked and writhed, and Dean smiled.
“Dichotomy of pleasure and pain, you said?” he murmured, raking a fingernail down. “Gonna give you ten more. Hard. Gonna keep my tongue inside you, though.”
Cas keened underneath him, and there were real tears dripping down his face. Dean slapped his ass as hard as he could, but every time Cas jerked and sobbed, he fucked himself further onto Dean’s tongue, and every time he did that, Dean spanked him again.
After ten blows, Dean didn’t know whether he was suffocating because of his tongue buried deep in the angel’s ass or the way Cas was writhing and begging and crying. He crawled up Cas’ body, pressing kisses on every available inch.
“So good,” he said, breathing hard against Cas’ neck. “You’re amazing. Fuck.”
He slid his hands down Cas’ back, slipping over his ass. “Gonna fuck you,” he whispered.
Cas dissolved into tears, and Dean panicked. “Cas. Cas, are you OK? I’m sorry, I’ll stop, I --”
Cas reached his arm back, scrabbling for Dean. “If you stop,” he said, with very forced control, “I will kill you.”
“Oh,” Dean breathed. He finally yanked his clothes off, fumbling for the lube, then spread it over his fingers. “Cas,” he said. “Cas, God, so good.”
“Please,” Cas croaked. “Please.”
“Gotta teach you patience one of these days,” Dean murmured, tracing cool, slick fingertips over hot skin. He bent and bit gently at the mark he’d already left with his teeth, then slid two fingers easily inside. “God, you’re aching for me, aren’t you?”
Cas didn’t reply, and Dean smacked him at the same time he crooked his fingers. “Manners, Castiel,” he said.
“Yes, I am,” Cas choked.
“Good boy,” Dean said, pulling his fingers out. “Good little angel.” He stroked himself, slicking himself, then pushed inside Castiel. “How does that feel?” he asked, biting back a groan.
“H-hurts,” Cas answered at once, trembling. “But feels -- so good. I think -- I think I understand. Contrast. Ju-juxtaposition.”
“Yeah,” Dean said, pressing a long kiss to Cas’ spine. “Pleasure,” thrusting his hips to hit the way he knew by now, “and pain.” He dragged his fingernails over the tender skin, then slapped both hands up once. “Tell me to fuck you.”
“Yes,” Cas cried out. “Please fuck me.”
“Even though it hurts?”
“Please,” Cas whispered, hands gripping the sheets.
“You’re so fuckin’ perfect,” Dean growled, finding a rhythm, and he could feel the heat of Cas’ skin against his hips. “So gorgeous.”
“Dean, I’m --”
Dean reached down, wrapped his hand Cas’ cock. “You did so good, little angel,” he said. “Come.” Cas spilled over his hand instantly. Dean gripped him around his waist, and the broken, fucked-out noises were enough to push him over the edge, coming with a sob.
He pulled out and lay back, panting.
“You,” he said. “Jesus. Out of everything, you’re going to be the death of me. I’m going to die by an angel of the Lord.”
Cas stretched and groaned. “The irony,” he said, “is not lost on me,” and Dean choked out an exhausted laugh. He wrapped his arms around the angel, pressing his mouth into his hair.
“That was fucking amazing,” Dean said. “Are you OK?”
Cas hummed. “Hurts,” he said, thoughtfully. “It hurts. I like it.”
“Good,” Dean said, kissing his skin.
“You hurt me, and I liked it,” Cas continued. “And I love you, but I want to hurt you, too. Is this a human thing?”
Dean rested his head against Cas’ shoulder.
“Yeah,” he said. “Yeah, I guess it is.”