Chapter Text
It wouldn’t be until nearly a year later that Castiel’s omega nature revealed itself again.
Dean liked to pretend he hadn’t thought about the scent in all that time. That the one and only occasion Cas had been without his powers, when that warm, impossible pie-sweetness had clung to his skin, had been a fluke, a one-time event.
He liked to believe he’d never dwelled on it after that.
But that was a lie.
Sometimes Dean thought it would fade. That with time, the memory would dull like old scars. But Cas’s scent wasn’t a memory; it was a stain. He could taste it in the back of his throat when he was alone.
He'd growled at Bobby once. Bobby. Just because he insinuated that Castiel might be betraying them all and siding with Crowley. Which seemed like crazy talk at the time. His omega- no. Castiel wouldn't do that to them. The mere insinuation that Cas might be going to the dark side almost made him go feral.
Then, after everything that happened, Dean wouldn't allow himself to even think about Castiel.
Him siding with Crowley. Absorbing all the souls of purgatory. Turning into a self-proclaimed god. Being controlled by the leviathans. Dying. Mourning him like crazy. Finding out he was alive but without memories. Taking Sam’s curse and falling into a coma.
And then he woke up.
Meg’s call came moments later. “He’s awake,” she said. “Not all there, but awake.”
Dean barely responded. Just grabbed the keys and peeled out of the lot, tires shrieking. Sam was already buckled in, silent.
The drive was a blur of streetlights and worry. Neither of them spoke. Not until the psychiatric hospital came into view. Dean parked hard. Sam exhaled.
Inside, everything smelled too clean. Too calm. A nurse looked up, but before she could speak, Meg leaned against the wall, arms crossed.
“Well,” she said, tilting her head. “Took you long enough.”
“Where is he?” Dean asked, ignoring Meg’s comment. She just started walking down the hall, and the brothers followed her closely.
As they made it to Cas’s room, Meg stood before the door and crossed her arms.
“Now, this is where I might need to stop you, misters.” Meg said, and Dean immediately frowned.
“The hell are you saying?” Dean almost snarled.
“Cas is not letting everyone into his room. I need to ask him if he wants to see you.” Meg smiled at them, pretending sweetness.
“The fuck? Get out of the way, Meg.” As he tried to walk past her, Meg was able to stop him with one simple phrase.
“He is nesting.” Dean didn't move.
“He is…what?” Sam asked.
“Nesting.” Meg repeated. “He woke up and just started flying all through the hospital, taking every pillow and blanket he could find and just…started nesting. It's pretty good, to be honest.” Dean frowned even further at that.
“He let you in?” He tried to hide his anger. He didn't succeed.
“Oh, Alpha, don't get it twisted,” she said with a smirk. “He’s not letting any other Alphas or Omegas in, but I’m functionally a Beta. He doesn’t see me as a threat.”
Dean’s jaw tightened, but some of the tension melted from his shoulders.
“And before you start freaking out,” Meg added, cocking her head, “he’s not presenting. No scent, no slick, no heat. Whatever this is, it’s not part of a heat cycle. He’s just… nesting. Instinctual comfort behavior, maybe. Post-trauma soothing. Who knows? Angel biology’s weird.”
Sam raised an eyebrow. “So he’s basically stress-decorating.”
Meg gave a wicked grin. “If by ‘decorating’ you mean cocooning himself in a six-foot throne of blankets and pillows, then yeah, sure.”
“Don't call a nest just decoration. It's weird.” Dean said and frowned.
“He is no omega to be nesting.” Meg added and raised an eyebrow. “Do you know something I don't?”
Before Dean could answer, they all heard the flap of wings, and suddenly, Castiel was in front of them all.
“Hello Dean.” He smiled and only looked at him.
“Heya, Cas.” Without another word, Castiel waved a hand, and just like that, Dean’s jacket vanished, only to reappear in Cas’s hands a heartbeat later. The angel was gone before Dean could so much as blink.
“I'm guessing that means you are welcome to his nest.” Meg said and laughed. Dean swallowed hard.
The thing was, nesting wasn’t casual. Especially not for someone like Cas, someone who wasn’t even presenting but still had the instincts like clockwork. The idea that Cas might want his scent woven into his space, that he might’ve picked Dean, was something warm and terrifying all at once.
He stood outside the room for a full minute before reaching for the door handle, pulse loud in his ears. The air was warm inside, filled with that low, thrumming grace Dean had come to recognize like the back of his hand.
And right there, at the center of the nest, blankets layered with meticulous care, feathers tucked in corners, his jacket still in Castiel's hands.
Dean took a shaky breath.
As Sam and Meg tried to enter behind Dean, Castiel sat a little straighter, and all the lights in the room began to flicker.
“I think this is our cue to leave.” Meg said, and Sam simply looked at her with an expression that read, “Ya think?”. Before walking out, Sam handed Dean the tablet.
“Ask him about it, Dean.” Said Sam and before Dean could close the door, he added, “And don't be too hard on him.”
Dean rolled his eyes in response. “C’mon, man.”
“No, I mean it. You know that nesting omegas are really vulnerable. Don't start with your bullshit.”
“He took your fucking barrier away. You almost died on me. I can't just forget that.”
“Yeah and then he fixed it. Just…” Sam sighed and crossed his arms. “Don't be bothering a nesting omega, okay?”
“He is not even really one.”
“Are you fucking kidding me right now? He went into heat in front of us. It took almost an hour to calm you down. He may not present on vessels, but he is still an omega.” Dean rolled his eyes but nodded.
“Okay. I'll be nice.” He gave his brother a sarcastic smile and finally entered the room alone.
“Hey, Cas.” The room smelled sterile, just like any hospital, really. There was no scent in the nest.
“Hello Dean.” The angel said, laying the jacket he just stole from him in the middle of the nest and taking a whole minute of complete silence and concentration to just make sure it was placed perfectly. “Oh, please. Come sit. I made it big enough for the two of us.” He smiled and sat on top of the jacket, smiling slightly at it.
Dean approached the nest and entered it carefully, tablet in hand. He had seen Omega's nests but never been inside one in his life. This was something that could never be taken lightly. A nest was an invitation, a courtship. One done only by omegas.
But Cas still smelled like nothing.
“So, uh, a nest for us?” Dean asked, and Cas nodded, smiling widely in response.
“Yes. Yes, of course. I'm sorry; I got so excited by you being here that I didn't even properly present it to you. I am so sorry, Dean. I know that it is more suitable to wait for an alpha’s offering before adding your scent to the nest.” He pointed to the jacket. “But oh, given our bond, I didn't think it would matter.”
Dean furrowed his brow. “Our what now?”
“Our bond,” Castiel echoed, as though it were the most obvious thing in the world. He tilted his head, studying Dean’s expression with patient fondness. “You let me scent you a while back. That constituted mutual agreement. We’re bonded now, Alpha.”
Dean’s ears went pink. “I-what?”
Before he could get out another word, Castiel moved closer, a low, instinctive rumble vibrating in his chest. He didn’t purr, not quite. The tension wasn’t exactly unfamiliar, but this… this was different. More ritual than flirtation.
Cas leaned in, nose brushing at Dean’s neck like he was reading a map only he could see, already reaching to tuck himself closer to Dean’s scent gland.
“Whoa, wait, Cas,” Dean tried, his voice pitching up half an octave. “We found a tablet. We opened it, and you woke up. Can you tell us anything about it?” He said as he tried to show it to him.
No answer. Castiel only hummed distractedly, nosing under Dean’s jaw now, the barest trace of scenting, claiming, curling at the edges of his mind.
“Seriously, Cas, you can’t keep ignoring this-” Dean hissed when the brush of Castiel’s mouth ghosted too close to his scent gland.
“Cas,” he said, breath catching, “I’ll let you scent me. Properly. Just-just talk to me about the tablet first.”
That did it.
Cas froze, then leaned back just far enough to meet his eyes. The look was unreadable, but a flicker of amusement danced at the corner of his mouth. “A bargain, then?”
Dean exhaled shakily. “Yeah, featherbrain. A deal.”
“You are so silly. Why would I bargain to smell my Alpha?” Okay. Thank God the angel’s scent was not present because he would really lose his mind.
“It-” He closed his eyes, gaining courage before speaking. “It will be a reward. If you are a good omega.”
“I am a good omega. I made a nest for you.” He almost seemed sad.
“I know you are. And it will make me really fucking happy if you tell me about this tablet, okay? And then you can scent me.” Dean didn’t like the way this conversation was going. Not with Cas. Not like this.
He’d always figured that if Castiel ever softened around him, really leaned into the Omega instincts Dean only saw once, it’d drive him out of his mind. He should be on fire right now. But instead?
He felt cold.
Cas was moving like an Omega, doing all the right things, even tilting his head in that obedient little arc that should’ve short-circuited Dean’s brain, but none of it rang true.
This wasn’t the Castiel he knew.
This wasn’t the Castiel he loved.
The fuck?
Dean didn't have time to dwell on that thought before the angel spoke again.
“Very well.” He said as he took the tablet. “Ah, the words of god.”
“From the god?”
“Yes. The words of my father set in stone by his scribe, metatron.” Dean blinked.
“And what does it say?”
Castiel looked down at it for a couple of seconds and then lifted his head towards Dean.
“Tree.” Cas said and Dean blinked. “Horse. I don't know, this wasn't meant for angels.” He kept the tablet on his lap and approached the hunter’s neck.
“Is that all?” Dean moved back.
“I cannot read it, Dean. Only a prophet, god or metatron himself can. I am sorry if I have disappointed you, I promise I won't do it again.” Dean looked at Castiel and simply sighed.
“You don’t disappoint me, Cas,” Dean said, voice low but firm. He held out an arm. “C’mere.”
Castiel stepped in, hesitating only a moment before he let himself be drawn close, face burying lightly into Dean’s neck. His breath caught, Dean’s scent was there, warm and rough and unmistakably his. It curled around him like a memory.
He nuzzled in closer. “Would you… scent me back?”
Dean froze.
Cas felt it, the hitch in his breath, the tension pulling his spine straight. He waited a second, then pulled back enough to look at Dean’s face, brows knitting. “What’s wrong?”
Dean swallowed, “I… I’m trying. But I don’t smell anything, Cas. You don't have a scent.”
Castiel blinked, shoulders falling just slightly, not enough to collapse, but enough that the quiet joy in his expression dimmed.
“Oh,” he said. Simple. Soft. “I am sorry Dean.” He backed away and stood up.
“Cas, no, I-” But before he could finish, the angel flew away, leaving the tablet without any support and falling to the ground, breaking in half. “God fucking damn it”
When he pushed open the door and stepped into the hallway, Sam and Meg looked up from where they were mid-conversation. Their expressions shifted at the sight of him, tense, expectant.
“He’s gone,” Dean said flatly. “Flew off. Dropped the damn tablet. It’s toast.”
Meg arched a brow. “Yeah, well. He doesn't like conflict. You must have done something wrong.”
Dean shot her a look, but Sam cut in first. “Where’d he go?”
Meg tapped her temple, thoughtful. “If he’s sulking, he’s probably in the dayroom.”
Dean didn’t reply. He just turned on his heel and walked off, jaw still tight, boots hitting the floor with purpose. As he saw the angel sitting alone in the dayroom, Dean stood before him.
“You realize you just broke God’s word?” The hunter said, trying to control the anger he was feeling at the moment. The angel didn't even look at him. Dean sat slowly in front of him. “It's Sam’s thing, isn't it? The curse you took. Is that why you are acting…like this?”
“Like what?” Castiel smiled again, like he wasn't sulking almost a minute ago.
“You know what I mean.” Castiel tilted his head in confusion. “Like an omega, Cas.” The angel just smiled.
“I am one. Did you like our nest?”
“Cas. Listen to me for a second.” The angel nodded. “I want you to button up your coat and help us take down Leviathans. Do you remember what you did?” And without saying anything, Cas held up the board game “Sorry!”. And with a simple shake of the box, the board and pieces of it appeared already set and prepared on the table. Dean blinked.
Then, as if it were the most natural thing in the world, Castiel handed him a game piece. “Your move.” Dean sighed, resigned, but he still started playing with the angel.
After a couple of seconds of playing without uttering a word, Dean spoke again.
“Cas, where can we find this, uh, Metatron? Is he still alive?”
“I'm sorry. I think you have to go back to start.” Dean sighed and moved the marker.
“This is important, Cas. I think Metatron could stop a lot of bad. You understand that?”
“Dean, it's your turn.”
“Dammit Cas!” He suddenly yelled, making the angel yelp. He pounded a fist on the table and swiped the board to the floor. “Forget the damn game!”
“I’m sorry, Dean,” he whispered as he stood up to pick up the pieces of the game.
“No, you’re not,” Dean shot back, hands still shaking. “You’re playing sorry. You think acting like an omega for me is gonna make me forgive you?”
That made Castiel still. His fingers froze around a game token. His gaze didn’t lift, but something flickered behind his lashes. “I’m not acting like an omega… for you,” he said, and his voice caught on the words. “I just… like it. It’s quieter this way. Easier.”
Dean’s expression shifted. The anger gave way to confusion, then discomfort. “Then why don’t you act like this all the time?”
Castiel stood slowly, eyes drifting over the mess of the room, then toward Dean. There was something hollow in his gaze, shame wrapped in resignation. “Because I forget how,” he said, barely audible.
There was a pause, heavy and aching.
“I’m sorry,” he repeated. Then came the low rush of wings and he was gone.
Dean sighed and stood up, walking down the hospital corridor, searching Castiel's room again. He had to be there now, in his nest. He paused at the corner before he turned down the hall that led to it.
Part of him expected Cas to already know he was coming. The guy had a way of feeling things, especially when Dean didn’t want them felt.
He turned.
And stopped cold.
There it was. His jacket.
Folded with characteristic care and set directly in front of Castiel’s door. Not thrown over a chair, not draped over a doorknob like something casually left behind. No, this was deliberate. Symbolic.
Dean’s breath caught in his throat. He was the only alpha who’d been allowed to step inside. Only his scent rested in the angel's nest.
And now the jacket was out here. Removed. Returned.
You’re not welcome anymore.
Dean stood there, staring down at it. He crouched, one hand brushing the collar. It was warm, like it had only just been set down.
Inside the room, he could hear movement. Soft footsteps, like pacing. Like maybe Cas was listening. Or maybe he wasn’t. Maybe he was curled up again, unspooling in a space that was made to be shared and now wasn’t.
Dean didn’t knock. He didn’t call out.
He placed one hand on the door, fingers splayed against the smooth surface. He thought about pushing it open. About demanding an explanation. About yelling until Cas had to look at him.
Instead, he just stood there.
Long enough to feel foolish. Long enough to feel the hurt settle low and tight in his chest.
He was about to leave the jacket exactly where he found it and walk away, but Castiel busted out of the room.
"Angels are attacking Sam.”
And they never talked about it again.