Chapter Text
Dean surfaced inside a cave with an opening so narrow, Castiel actually had to pull his wings in tightly against his body and coast to a stop on the little strip of rocky land along the waterline.
“Welcome to the Dean Cave,” Dean said proudly. He hauled himself out of the water and spun around on the curve of his tail. “Decorated by yours truly.”
Castiel looked around the cave with interest. He had originally seen only rock, but once he looked more closely, he noticed bits of driftwood, boat propellors, statues covered with barnacles, and a very waterlogged couch.
“Why are there claw marks in the wood?”
Dean’s smile faltered. “Oh, that. Michael, my previous mate, kind of tore up the place when he found out I didn’t catch."
“Catch what?”
“Catch pregnant.” Dean sighed. “I might not act the part, but I’m an omega. I’m meant to find a nice little cave, spruce the place up and send out pheromones to attract a mate. And then stay put in this cave for the rest of my life, raising litters of young. But I’m infertile so I’m basically useless as an omega.”
“You can’t say something like that. You’re meant for so much more than being trapped away in a cave for the rest of your life. I’ve seen you swim. You were meant for freedom.”
“Yeah, well, I wouldn’t mind raising a pup or two,” Dean said wistfully. “If I could find an open-minded alpha who saw me as more than a breeder. It gets lonely sometimes, without a mate and without any pups. But sure, I guess living on my own has its perks.” He carefully turned over the piece of driftwood so the claw marks were no longer visible.
“I didn’t mean to make you self-conscious about your dwelling,” Castiel said.
“Nah, it’s cool. Just means I need to go diving for more junk to decorate with. There’s no shortage of fun things I can find. Humans are such wasteful creatures. They toss so many perfectly good items into the ocean.” His eyes flicked over to Castiel. “No offense.”
“None taken,” Castiel said serenely. “I’m not human.”
“Right. Have to keep telling myself that. You sure look human. Besides the big-ass wings, of course.”
“That is the idea,” Castiel said. “An angel’s true form is a wave of celestial intent but our brightness blinds mortal eyes. We had to take physical bodies to walk among the humans.” His wings were dry now, so he carefully folded them back inside his vessel.
The fact that Castiel was able to confine his entire celestial form into a specially-made human body never failed to amaze him. He tried to explain to Dean that his wings were an extension of his grace that mortals could actually see, the mechanics of inhabiting a human body, and his preparation for an actual mission on Earth.
Dean’s furrowed brow probably meant he really didn’t understand, but then again, he wasn’t an angel. Perhaps only angels found the operation of vessels fascinating to think about.
“Okay, so, is the tax accountant model popular with you guys or are you the only one?”
“A model? I don’t understand, Dean. I consulted with my brother Balthazar and he specially designed this body. I shouldn’t resemble anyone currently living. Have you seen a tax accountant with the same form?”
Dean pinched the bridge of his nose. “It’s not the body. It’s the clothes, man. Especially that long coat.”
Castiel frowned. “What’s wrong with my coat?”
“Nothing. It’s just….if you have all the options in the world, why would you pick that?”
“It has movement,” Castiel said. “If I can’t feel the wind beneath my wings, this is the next best thing.” He twirled around, showing how the coat flared out and swished around his knees.
“God, you’re adorable,” Dean said with a sigh. “It just isn’t fair.”
“Why? What’s unfair about it?”
“Never mind,” Dean said with a dismissive hand wave. “Is the body and the clothes a set or do they come off?”
Castiel snapped his fingers and his vessel was completely naked.
“Wow, you definitely picked an attractive model,” Dean said with an appreciative whistle. He heaved himself closer. “I know alphas who would kill for those abs.”
Castiel twitched as Dean trailed a hand across his abdomen.
Dean’s eyes widened. “You can feel that?”
“Yes, of course. My vessel was built as a functional human body. I can feel every sensation a human can. Of course, I can also suppress these senses if I wish and I’ll probably have to do so if I’m ever sent on a mission to battle the forces of evil, but in the meantime, I choose to feel.”
“Well, you deserve to experience all the good things life has to offer.”
“And the bad,” Castiel said. “I won’t truly be able to understand the human experience if I do not also feel pain and suffering.”
“Jesus,” Dean said. “You really are an angel. Putting yourself through horrible matings like I’ve done, just so you can sympathize with those that have.”
“Well, I haven’t gotten around to those kinds of experiences yet.”
Dean’s jaw dropped. “You haven’t had sex? But it’s such a universal human experience.”
Castiel rubbed the back of his neck. “I just haven’t had the occasion for it.”
Truth be told, he had been too afraid to try. At first, he worried that he wouldn’t have proper control over his vessel and accidentally hurting a potential partner. And then he was worried about his lack of experience outing him as being nonhuman. And of course, there was the whole business of entering into a relationship while pretending to be human. That kind of deception didn’t sit quite right with Castiel.
Dean’s face lit up. “We should have sex.”
Castiel was alarmed. “What? Why?”
“Why not? You get to add sex with a merman to your list of experiences and I get to find out what it’s like to have sex with a human…sort of. And I get to finally find out what it’s like to have sex with a virgin. All of my previous mates were older and more experienced and they made sure I was aware of it. Take it from me. You want your first time to be with someone who won’t judge you for being an awkward virgin.” Dean gently stroked Castiel’s chest. “Please, Cas. Let me do this for you.”
Castiel shuddered. Dean’s hands were surprisingly warm and rough. It was very pleasing. He swallowed and forced himself to speak. “If I touch you, I’ll also be touching you with my grace.”
“It’s fine. I trust you. Your weirdness is kind of endearing now.”
Castiel placed a careful hand on Dean’s shoulder. Immediately, he was bombarded with knowledge. He saw images of mer skeletal structures, musculature, and the respiratory system. He understood mer culture and mating rituals.
And then it all narrowed down to Dean.
Dean raising his younger brother after their mother died because John Winchester was an alpha and raising young was beneath him, the pain of Sam leaving for warmer waters while Dean was forbidden from straying too far from clan territory, enduring rough mating and being abandoned again and again when he failed to bear offspring, the hope that each new alpha he mated with would finally be the one who stayed. Dean had all the reason in the world to be angry and bitter all the time, but his soul was still full of love and goodness.
Dean Winchester deserved to be loved.
“Cas? You okay?” Dean asked. “You look like you’re having a stroke.”
“I’m okay,” Castiel said. “It’s just very overwhelming to know so much in such a short time. Your species is much more complex than a dolphin or a trout.”
Dean chuckled. “Tell me about it.”
“But I’ve gained much useful knowledge.” He slid a hand down Dean’s back, just past the junction of skin and tail and probed for the weak spot in the scales.
“Well, damn,” Dean said. “First try. Definitely not the fumbling virgin I expected.” He arched his back and the scales split apart under Castiel’s hand.
“This also feels different than I expected,” Castiel admitted. He buried a finger up to the knuckle in Dean’s warm, velvety hole.
“Just wait until I get turned on,” Dean said. “I’ll be all slick inside and you can shove your dick right in.”
Castiel frowned. “I most certainly will not just shove it in.” He’d seen how much pain Dean had put up with when his mates didn’t bother taking time with him. And now that he knew how mer anatomy worked, he knew how to make things easier for Dean.
Castiel continued stroking Dean’s insides with a finger until he was very slick and begging for Castiel to stop playing with him and just put it in already. And even then, Castiel eased in slowly, giving Dean’s body time to adjust. After he bottomed out, he stayed still for a moment, having to adjust himself to the feel of Dean’s muscles rippling around him.
“Oh, this feels incredible.”
Dean grinned widely. “We’re just getting started, Cas. I’m good at sex. Babymaking, not so much. But I fuck like a champion.”
Castiel really wished Dean wouldn’t make such disparaging remarks. He hoped one day that Dean would find the alpha of his dreams and have all the children he wanted.
Dean raised himself up on his hands and levered himself back down with his tail.
It was probably a very unconventional way of having sex, but it was working. Dean was making very appreciative sounds and his muscles tightened around Castiel’s penis so perfectly.
As his pleasure built, grace flared under his skin. For the first time, Castiel found himself struggling to confine his true form to his vessel.
“Cover your eyes,” he ordered. He hoped Dean had obeyed. He was unable to hold himself back any longer.
He cried out in pleasure. Grace streamed out of his eyes, his wings unfurled and beat the air, and his entire vessel shuddered like it would shake apart.
With an effort, Castiel reigned himself in, withdrawing his grace and wings back into his body.
“Is it safe yet?” Dean asked. “I promise I didn’t look, but holy hell, I could see some kind of light show happening behind my eyes.”
“I apologize,” Castiel said. “I should have been more in control.”
“No way. Never apologize for that. I’m just such a good fuck that an angel lost his mind. What a compliment.”
Castiel rolled his eyes. “Well, you should be safe-oh!” He squinted against the sudden burst of bright white light.
When the light cleared,Gabriel was standing in the middle of the cave.
“Cassie!” He smirked. “You know, when I told you to play with your body, this isn’t what I expected you to do.”
Castiel scrambled for his clothing. “My apologies, Gabriel. This is very unprofessional of me.”
“Who the hell is this?” Dean demanded.
“This is my superior, the archangel Gabriel.”
“Oh fuck.” Dean said.
“Oh fuck sound about right,” Gabriel said with a suggestive eyebrow waggle. “Hey there, Dean-o. You treating my baby brother right?”
Dean gaped. “You’re his brother? And you showed up to watch us have sex?”
“I didn’t know you two were doing the do,” Gabriel said indignantly. “Cassie here just expelled a huge amount of grace. That’s usually a sign and angel’s been attacked and of course I followed the distress signal because I’m a good, caring brother. But I’m so pleased it’s just a little extracurricular activities. Good for you, Cas. You make me proud.”
Castiel blinked. “You’re not upset with me?”
“Upset? Why would I be upset?”
Castiel’s wings drooped. “I’ve been shirking my duties.”
“Shirking your duties? You were told to experience everything you could in a month so you could pass as human. I didn’t expect you to immediately go for the kinky, interspecies stuff but you’ve always been kind of a rebel. But now you’re in a really good position for when a mission comes up. We’ll have to work around Dean’s pregnancy, of course, but-”
“Now you just wait a minute,” Dean said. He raised himself onto the base of his tail. “I can’t be pregnant.”
“Of course you are. You kids didn’t bother to use protection. I don’t see why you’re surprised by the outcome.”
“Protection?” Castiel frowned. “I have my angel blade.”
“I can’t get pregnant,” Dean said. “I’m infertile. I’ve gone through a dozen mating cycles already and none of them took.”
“Well, this one did." Gabriel raised an eyebrow. "You did will for Dean to get pregnant, didn’t you, Cassie?”
Castiel thought back to his fervent wishes for Dean’s future. “I…well, yes. Dean wanted children and wanted that to happen for him. I didn’t expect they would be mine.”
"You did this, Cas? You made me pregnant with your angel magic?" Dean beamed and rubbed a hand over his stomach. "I'm so lucky to have met you. This is all I've ever wanted."
Gabriel cleared his throat. “As I was saying, this’ll be a good thing. The two of you can work the coast. I’ll get you settled in with a beach house and a boat and an identity as a fisherman. There’s always shit going down in Florida and nobody wants to touch it. Maybe the two of you can finally make sense of things. Anyway, it’s your problem now. Congrats, kids!”
He disappeared in another burst of light.
“Your brother’s even weirder than you are,” Dean sighed. “But hey, free trip to Florida.”
“Florida sounds…unpleasant. More like a punishment than a mission.”
Dean shrugged. “Florida isn’t that bad, from what I hear. Full of outrageously stupid people, but at least it’s supposed to be pretty.” He grinned. “Kind of sounds a little like me. I may be pretty, but-”
“No,” Castiel said firmly. “You are bearing my offspring. You are not broken. You never were, but now you have proof of that. So there will be no more disparaging remarks about yourself. Our children will not grow up disrespecting your value.”
Dean blinked. “Definitely going to have to get used to that.”
“Yes,” Castiel said. “You will.” He was going to make it his mission to make sure Dean realized his own worth.