Warnings:

Contains themes of a sexual nature, including a BDSM sub/dom style relationship. There's also a panic attack written about in detail based on my own personal experiences, so it should feel quite real. Includes Dean's general feeling of self-hatred as well. Just watch out for that and please don't read if you feel it'll negatively affect you.

My first ever Destiel and my first ever smut (if you can even deem it that I guess), so feedback, whether it be positive or negative, would be amazing and v helpful.

"Ohmygod this heat is unbearable," Dean complained, laying naked in his own puddle of bed sweat.

"I think it's fine," Cas smirked, also naked at Dean's insistence of the situation otherwise feeling weird, thankful that his side of the bed was entirely sweat-free.

"You would, Cas. You don't get hot or cold. Trust me, for humans? Not fun."

"Dean, I know you're uncomfortable but it's not my fault that you broke the AC."

"Hey!"

"Repeat after me; Grenade launchers are not toys."

"Grenade launchers are not toys," Dean deadpanned.

"Good boy," Cas praised, rolling over, grabbing Dean and running a possessive hand over his boyfriend's ass. Dean's stomach coiled. Yes, please. Cas couldn't help himself. He stroked over Dean's body and kissed him full on his lips.

Dean groaned, feeling his angel's erection pressing into his leg.

"Cas, you can't say that - you know what it does to me."

"That is exactly why I said it, princess. It's been two weeks, Dean. The bunker is empty and we are finally alone. I am an angel of the lord. I want you, and I get what I want."

"God, I have ruined you, Castiel."

"Dean, I will explode. Which has happened before and honestly I'd rather not repeat the experience."

"'S too hot, Cas," Dean reasoned, rolling away from him in bed. He was too tired to come up with one of his usual sassy responses like 'yeah, well I'll melt.'

That's it, Cas decided.

Cas shot out of bed, the furniture creaking with the sudden movement and swiftly left the room, uncaring that he was going through the bunker naked. Sam and Jack weren't there to stop him anymore. A few short minutes later, he returned with two bowls. Dean shivered as he heard the ice clinking against the glass of one of them. Oh, what now?

"Cas, I'm not-"

Ignoring his lover's objections, he grabbed the man and flung him against the nearby wall with a thunk.

"I want to play, pet," Cas said in the most sinful voice Dean had ever heard. He felt his half-hard erection bob with excitement.

Dean gulped.

"Yes, Sir."

"Good boy."

Dean could feel the scratch surface of the exposed brick against his back, already leaving scratches. Oh, he was in for a rough time. He couldn't wait.

"Spread your legs, baby."

After a shocked pause, Dean muttered all he felt he could. "Yeah… sure, Cas, I can do that."

Cas grabbed Dean by the throat, applied gentle pressure and brought his lips to the shell of his lover's ear and whispered: "No, what's my name, pet?"

"Sir. Yes, Sir."

Cas smiled a sadistic smile. "Much better."

"Close your eyes."

Dean tried to swallow hard, but found there was no saliva in his mouth. He just took a deep breath and obeyed, soon feeling the usual silk cloth tied as a blindfold.

"What's your safe word, pet?"

"Cherry."

In response, Cas mojo'ed up his favourite chains and warped them around Dean. Those ones that put his beautiful boyfriend in an X shape. He loved having him like this - so beautifully accessible for almost anything Cas could want to do to him. Dean gasped at the feeling of the sudden cold around his wrists and ankles. It was enough to send chills through his body in spite of the immense heat throughout the bunker.

Cas had a rule. He knew that Dean would take whatever was given from him, no questions asked. He knew that Dean would allow himself to be used and abused if that's what Cas wanted. When Cas used Dean's name during sex or foreplay, it was an indication to him that he wasn't playing. That he was being sincere, and needed Dean to hear what he was saying. It was just his way of making sure Dean could separate play from the rest of their active lives.

Cas tenderly lifted Dean's blindfold and was met with a questioning look. "I love you, Dean. So much."

The other man's face softened into a gentle smile. "I know, Cas. I love you too." Cas couldn't help himself. He placed a gentle kiss to Dean's lips smiling into it. He loved being Dean's dom. But he lived for the soft moments that came with just being his boyfriend. Not wanting Dean to lose momentum, Cas placed feather-light kisses along his jaw, gently sucking as he went. His lips traced all the way up to that sweet spot that sat just at the corner of Dean's jaw, revelling in the strangled moan that came from his lover's lips.

"Alright, pet," Cas smiled wickedly, pushing the blindfold back down the other man's eyes. "Playtime."

Dean heard more of the ice clinking around in the bowl, remaining comfortably between insanely aroused and apprehensive.

All too suddenly, Cas engulfed Dean's member in his mouth. Dean gasped, hitching his breath at the familiar but never tiresome feeling.

"You still too hot, pet?" Cas didn't give Dean time to answer before answering his own question, "well, let's see if we can remedy that," popping an ice cube in his mouth and inhaling Dean once again.

Dean nearly came on the spot. His head smacked back against the wall and his hips jolted forward, his breath juddering. "That good, huh, baby?" Dean nodded furiously, eyes smarting with gratitude for the beautiful new sensation. Dean couldn't see, but Castiel had been resting his fingers in the other bowl - the one filled with freezing cold water. All very suddenly, Cas circled his finger around Dean's entrance. Dean's chains rattled with the movement of his body. He desperately tried to push down onto his boyfriend's finger, but he placed it just out of reach, the Seraph's digit barely skimming Dean's puckered and pink hole.

"Oh, I love teasing you, pet," Castiel said, taking Dean's cock in his now cold hand and pumping slowly. The noise coming from Dean was just sinful. Cas was going to come from that alone if he wasn't careful. "But I just can't concentrate with all that racket you're making," Castiel chastised, shoving his forefinger between Dean's teeth, like you would with a horse and the head harness. Not once slowing his movement on Dean, Cas grabbed the blindfold and dragged it down his face into a makeshift gag, stopping first to pop an ice cube into Dean's mouth.

Cas noticed Dean's telltale signs of coming. His legs shook, his head flopped forward, his muscles tightened.

"Uh-uh. Don't you dare," Cas warned, tightening his grip around the base of Dean's dick. "You are not to come until I say so." Dean whimpered and very nearly cried.

Cas snapped his fingers and Dean's wrist shackles undid themselves, Dean dramatically falling to his knees. "I have been so kind to you, pet. Time for you to return the favour." Dean's gag was pulled down again to his neck. "You better suck it well, baby. Suck it like your ass depends on it. Because it does."

Dean desperately blew Castiel, pulling out all of the stops. He swirled his tongue around the head, licked over the slit. Cas was mind blown. Just as Dean took Cas all the way into his mouth, Cas pulled back on the former blindfold/gag that was now sitting around Dean's neck. The sensations were overwhelming. Dean came with such force that he screamed through his orgasm, the vibrations going straight through Cas' dick. Cas couldn't help himself. Long white ribbons of himself shot down Dean's throat. Dean took it like a champ, not missing any of it.

"Look at the mess you've made, pet."

"I'm sorry, Sir."

"You can make up for it. Face down, ass up."

Dean obeyed, almost falling to the floor in his fervour. Cas delivered five rapid smacks to Dean's ass, no time to recover between, and no time to prepare himself for what happened next. Cas slammed his dick into Dean's hole with fervour, watching Dean's ass swallow it greedily. No preparation. No lube. Two weeks. Dean was in heaven.

But holy hell did it hurt.

Cas barely stilled for a second, too engulfed in his own want to be able to stop himself fucking mercilessly into Dean.

Dean didn't know what to do with himself. His mind was racing. Cas felt so good. But something was wrong. He didn't know what it was, but he could feel it building in his chest, rising to his throat. He froze.

Although lost in his own slice of heaven, Cas still felt his lover tense up. And something about Dean's demeanour told Cas that it wasn't in a good way.

"Dean?" He enquired. Stilling to a halt but not pulling out, he placed a gentle hand on the back of his human's head and stroked a thumb over the short hair at the nape of his neck. Dean's breathing was heavier now, like he couldn't catch it. When there was no response, Cas removed himself and Dean was immediately flipped over to lie on his back, Castiel catching his eyes, concerned at the blown pupils. Dean closed his hands into fists and pulled his arms inwards, as if preparing himself to fight.

Cas was panicking. Dean didn't do this. Ever. He had no idea what to even do for Dean in this circumstance. If Dean was angry, he would let Dean scream and then hold him when the anger dissolved into tears until he calmed down. When Dean was upset, Cas would let Dean cry it out by himself for a bit and then talk about it rationally. Dean hated showing weakness. But this was the ultimate weakness. Something had triggered a panic attack in Dean whilst he was being dominated by a cosmic being during rough anal sex. It wasn't really possible to be more vulnerable than that.

Think, Castiel, think, he chastised himself. All Cas could think of was a hug. And then he realised that's exactly what Dean needed. Not because it was a damn hug, but he needed to feel secure. There's a certain release that comes with an intense pressure. Dean slept with a weighted blanket, for god's sake, of course he needed to feel restricted in order to be freed of the things weighing down on him. It also explains a number of Dean's kinks, but Cas couldn't get into that now.

Cas pulled Dean's arms from in front of his chest and laid his body weight over the top of Dean. With one of his knees in between Dean's thighs to pin him down, and his forearms either side of his head, stroking through the hair by his temples, the angel essentially covered him with a blanket of Cas-smelling security.

"Dean, shhh," Cas soothed, kissing over his forehead repeatedly. "You're okay. You're safe. I've got you." Cas lowered his mouth to Dean's ear. "Breathe for me, baby, breathe," he whispered. "Can you hear me in that busy head of yours?" Cas lifted his head to try to meet Dean's eyes and tilted his head to the side. "Hm?"

Dean nodded slowly, actively not looking at Cas. Okay, a little progress.

"Good," he praised. "Do it with me, Dean. Let's breathe. Ready?" He asked, although he didn't wait for an answer. "In through the nose…" He waited for Dean to obey, but he never did. "Come on, Dean. It won't work if you don't do it with me. Can you look at me?"

Luckily, this time, Dean found it in himself to look at Cas. Their eyes met and Cas couldn't help but smile. "There's those beautiful eyes of yours," Cas praised. "Okay, now work with me here, in through the nose," Cas demonstrated, thanking the heavens that Dean decided to cooperate this time. "Yes, Dean, good. Keep going."

Eventually, Dean managed to calm himself down with the help of Cas. They breathed deeply together for a solid 5 minutes, Cas continuing to stroke his fingers through the front of Dean's hair.

Once Dean seemed to have calmed down, Cas couldn't wait anymore. He needed answers. "Dean," he asked so gently that he was surprised it was audible. "What happened?"

No, Dean thought. Absolutely not would he want people to be careful around him. He was Dean fucking Winchester. God punching, ass-kicking, demon-slaying Dean Winchester. The Dean Winchester that all monsters feared. And if they weren't scared, then they should be. He was a badass. Not some pathetic, weak coward like his father always said he was. No. Never. He hardened his stare and rolled himself from underneath Cas, rising from the bed.

Cas couldn't help feel the disappointment as he watched Dean build his walls back up and put some clothes from the floor on, cringing at how they clung to his sweaty body. "I'm fine, Cas."

"No, Dean, you're not fine. You just had a panic attack during sex."

"Jesus Christ, what am I, a fourteen-year-old girl? I just got overwhelmed."

"Dean, please don't do this. I love you, and-"

"Stop it, Cas," he demanded. "I don't get 'panic attacks'. I told you-"

Dean turned his back to Cas, searching for a new shirt. Castiel huffed.

"Dean, I can't think of anyone in the world who could endure all the crap you have and still live to tell the tale, let alone do it without increased anxiety. Maybe you should talk-" he laid a hand on his lover's shoulder, but was cut off by his own anguished scream at Dean twisting his arm behind his back.

"Oh my god," he said in possibly the smallest voice he could muster, the volume barely above that of a thought. Suddenly, Cas was released and Dean pulled him into a tight embrace. If Cas needed to breathe, the air would've been knocked out of him.

"Sir, I'm sorry." Castiel felt he was getting emotional whiplash from Dean's back and forth. He was calling him Sir now? After acting like they weren't even dating?

"Dean," Cas began, cementing that he wasn't expecting any of their normal rules to apply here. "I'm just worried. I don't understand what triggered it."

Okay, Dean thought to himself. Either you can keep pissing him off until he eventually gets tired of your shit and abandons you like fucking everyone else… or you can talk to him. Maybe he can help deal with your stupid little girl emotional shit.

"I don't understand it either."

"I am so sorry, Dean, I should never have pushed you." Cas took a risk. "What were you feeling? What were you thinking?"

"I honestly couldn't even tell you. I just felt it. Just building in my stomach, and rising in my chest. Like I was choking on it." He couldn't help himself now. Words and tears poured from his body at a rate of knots. "There wasn't even a specific thing I was thinking. It was just panic building and building until it swarmed my body. Usually, it's about my dad or losing you or something," his voice cracked, "happening to Sammy."

Cas' eyes widened as he recognised the panic building again in Dean. He threw his previously limp arms around his human and squeezed tightly. Usually, Castiel placed his arms around Dean's neck, but this time, he wrapped his arms around his waist and used his forearms to press into Dean's upper back, crushing their bodies together, whilst whispering assurances into his ear.

"I've got you, Dean. Sam's okay, and I am never letting you go."