A/N: First of all, if you've been following The Secret Ingredient, please don't panic. I have not abandoned it. I'll be coming back to it in February with a very special Valentine's Day chapter. ;)

This was written for the Secret Santa Fic Exchange in the Destiel - Writers & Readers group on Facebook, and I think I managed to work in almost every single one of my giftee's trope requests. Turns out she meant them as options, not a challenge. Lol. No turning back now.

Fair warning. This story is ABO and contains mentions of mpreg. There is also light BDSM with the omega as the Dom and the alpha as the sub. If any of those things aren't your cup of tea, please move along.

A few thank yous are in order before we begin. First and always, to my husband AJ. This has been one hell of a year, and I honestly don't think I could have survived it without you, neshama. Second, to my editor and best friend, Eyum daRelmera. From wrangling my ellipsis to making sure I didn't forget about Dean's glasses to teaching me about safe BDSM practices, you have made this story infinitely better than I ever could have on my own and you have made my life infinitely brighter with your mere presence. 💖😸. And last but definitely not least, to Dani, who not only beta read this story for me but also organized the whole Fic Exchange in the first place, so this story literally would not exist without you.

This is a WIP. It is outlined to be 8 chapters total and will hopefully update once a week. Please be patient with me if I miss a week here and there. It's been a rough year, and my mental health has taken a beating.

Happy reading, and please remember to leave a review if you like it. =)

Chapter One

Dean jolted awake as the front door slammed so hard the windows vibrated. He sat up, rubbing the sleep from his eyes and groping for his glasses among the takeout containers on the coffee table, the debris of his lonely dinner. He didn't need to see to know who had slammed the door as the rotting leaves and stagnant water smell of Cas' anger was assaulting his nose as badly as the noise had assaulted his ears. But once the blurry figure in front of him came into focus, he saw that Cas wasn't just ordinary pissed. The omega was pale and shaking, his eyes glowing blue lightning and his face ashen. His expression was simultaneously livid and terrified.

Dean leapt up and tugged Cas over to the couch, pushing him down and sitting next to him. He could tell from the way Cas pliantly let the alpha lead him that he wasn't fully present in his own body, so Dean quietly held his hand, waiting for him to come back from wherever he'd gone. It was a miracle that Cas had made it safely home in this state.

Finally Cas spoke, his voice flat and toneless. "I'm sorry I woke you."

"It's okay," Dean reassured him. "Just tell me what happened. I take it family dinner didn't go well."

Cas snorted. "Dinner was fine, Hannah's cooking notwithstanding. It was after dinner that things went to hell. Once Jack was in bed, I showed Michael the bank statements like you suggested. The numbers speak for themselves. I am more than ready to provide a stable home for Jack. They promised that when I was on my feet, they would relinquish custody back to me." Cas' voice was growing less flat and emotionless, rising to match his scent.

Dean's heart sank. "What was his excuse this time?"

The hand Dean wasn't holding balled into a fist on Cas' thigh, nails digging neat little crescents into his palm. "That it's 'better for a child to grow up in a two parent home with both alpha and omega role models'," Cas parroted bitterly. "So until I'm mated, they feel that it's in Jack's 'best interest' to remain with them."

"That's bullshit."

"I know," Cas said, rolling his eyes, a little of his usual sassy self peeking through, "but I did make them Jack's legal guardians, idiot that I was, so —"

"You weren't an idiot," Dean interrupted. "You were trying to take care of your kid, and you didn't have a lot of options at the time. You couldn't know that they would break their promise. They were your family!"

Cas didn't look comforted. In fact he suddenly looked guilty, the sour scent of it rising to Dean's nose. He disentangled his fingers from Dean's and avoided the alpha's eyes. "There's more."

Dread curled in the pit of Dean's stomach. He pictured Michael introducing Cas to some rich, handsome, nice smelling alpha, promising that as soon as they mated and married, he could have Jack to raise with his new husband. Or wife. From Cas' stories about his childhood, Dean had gathered that his family were old-fashioned. They would probably prefer to see Cas mated to a female alpha if it was up to them.

Either way, the thought made Dean feel sick to his stomach, which was weird. Their little arrangement was far from monogamous, and it had never bothered Dean that Cas let other alphas fuck him. He even got to watch sometimes which was all kinds of hot.

But mating… mating was different. Cas wouldn't just be warming another alpha's bed for a night or a weekend. He would belong to the alpha, and Dean would never be allowed to touch him again, not even to just put an arm around him while they watched Dr. Sexy together on the couch, or to kiss him chastely on the lips.

And he highly doubted that any alpha chosen by Michael would appreciate or accommodate Cas' particular preferences in the bedroom. No, they would want him to meekly present for them every night or else lie docilely on his back like a dog showing its belly. Cas would spend the rest of his life miserable and unsatisfied, but he'd endure it. For Jack he would do anything.

"Please believe me, Dean," Cas was saying, gaze locked on the floor and wringing his hands. "I… I didn't mean to do it. I… I just panicked. He was going on and on about mating, and I couldn't think. I had to say something to shut him up."

Dean's world was crumbling around him. Maybe he was still asleep and this was a bad dream; he prayed for that. He'd long been prepared for the possibility that Cas would fall in love someday. He knew that Cas didn't feel about him the same way he felt about the omega, which was why he'd always kept those feelings strictly to himself and never asked for more than Cas could give. So if someone had come along who made Cas as happy as Cas made Dean, Dean would have let him go. It would hurt like hell, but not like this. To lose him like this, watch him marry some rich knothead who didn't even know how lucky they were, who would make him suppress his true nature and play the good, submissive little omega… that was worse than anything else Dean could imagine. This burned inside him.

"So I told him you were courting me and we were talking about mating soon."

"Wait. What?" In the grip of his own panic, Dean had almost missed what Cas said.

Cas, mistaking the lingering acrid notes of grief in Dean's scent for anger, hid his face in his hands. "I'm sorry. I'm so sorry. I'll call them tomorrow and tell them it was a lie."

"Are you kidding?! No! Cas, this is perfect!"

Cas separated his fingers the barest inch and peered through them. "It is?" he said skeptically.

"Yes! Don't you see?" Dean dragged Cas' hands away from his face and squeezed them. "We pretend to be a couple just long enough to convince your brother that you're settling down."

It wouldn't be that hard. People were always assuming they were a couple no matter how many times they explained that you didn't need to have romantic feelings for someone in order to express your affection for them physically. (Well, the fact was that Dean did actually have romantic feelings for Cas, but that is entirely irrelevant. Cas is twice as touchy feely as Dean is.)

"Once they sign over custody and it's all legal, we can drop the act. There's no law against unmated omegas raising kids on their own. It's just stuck up knotheads like Michael who think there should be."

A smile was finally, finally breaking over Cas' face like a sunrise. "That could work," he said. Then he suddenly turned wide blue eyes on Dean, and fuck, did he have any idea what that did to Dean's heart? "You would really do that for me?"

"To help you get your son back? Of course I will." And, y'know, because I'm hopelessly in love with you and stuff, Dean added silently. Yes, pretending to be Cas' almost-mate would be no hardship. He'd just have to be careful not to pretend too well and tip off his best friend and sometimes casual lover to his decidedly un-platonic and non-casual feelings for him.

Cas was calming down, but Dean could still scent the sour notes of his grief and panic in the air. He let go of one of the omega's hands and gently cupped the back of his neck, drawing him in. Cas understood immediately what Dean was offering, happily burying his nose in Dean's scent gland and breathing deep. Dean wrapped his arms around the omega and leaned back into the couch cushions so that they could scent each other in comfort.

Soon, Cas smelled clean and verdant again, like a rain washed forest, but he made no attempt to leave Dean's arms, and Dean definitely wasn't going to tell him to. He secretly liked cuddling even more than sex, and cuddling with Cas was better than sex and pie put togeth-

Well, it could certainly give pie some stiff competition.

A while later, Cas' scent changed again, taking on the electric tang of a thunderstorm. Like Pavlov's dog, Dean's dick instantly chubbed up in response.

"Color?" Cas murmured, his mouth so close to Dean's ear that Dean could feel his lips move and the flick of his tongue.

"Green," Dean said hoarsely.

Cas drew back and gave him a searching look. "You're sure? You're not just saying that because I need it tonight?"

"No. I want to, Omega."

Cas nodded, satisfied that Dean was telling the truth. Then the lines of his face seemed to sharpen as he slipped into his Dom persona, and Dean's dick gave another desperate twitch. "I'm going to take a shower. Go to my room, undress, and wait for me. May I fuck you tonight?"

Dean's pants were getting painfully tight. "Yes, please, Omega," he said, his voice squeaking a little.

Cas smiled like a cat that got the cream. "Then you may prep yourself while you wait. You may give yourself as much pleasure as you wish while doing so, but you may not come. And I give you fair warning," he raised one eyebrow in that way of his that always made Dean's blood boil, "I'm not going to go easy on you tonight, and if you come before I tell you to, I will be very disappointed. Do you understand?"

"Yes, Omega."

"Good. Then go wait for me."

The townhouse they rented together had three bedrooms. One was Dean's, one was Cas', and one was Jack's when he spent the weekend with Cas. Hopefully, one day soon, Jack would live there full time. Dean wasn't sure how having a kid in the house would affect their arrangement, but even if Cas didn't want to scene anymore, Dean could live with that. It would be a small price to pay for Cas to be able to tuck his kid in and read him a bedtime story every night. The sadness in Cas' eyes every time Jack went back to Michael and Hannah's after a visit just killed Dean.

He heard the shower start down the hall as he went into Cas' room. It was nothing like the popular image of a BDSM "sex dungeon" or whatever the kids were calling it these days. Cas had a normal bedroom with a king size bed, nightstand, and dresser. The headboard was upholstered in black faux leather with silver studs, but it was mostly hidden behind a truly absurd number of navy, black, and cream throw pillows that matched the pattern on the thick, navy blue comforter.

There was a double picture frame on the nightstand. One side held a picture that Dean had taken of Cas in the hospital, looking exhausted but happy, cradling newborn Jack to his chest. The infant's hair was still damp and plastered flat to his tiny skull from squeezing his way out of his father. The other side of the frame showed a chubby five-year-old laying in a pile of fallen leaves in the townhouse's backyard. Cas had taken the picture with his phone on Jack's last visit, and even though it was a little blurry because Cas was a terrible photographer, Jack looked happier than he ever did in the pictures Hannah occasionally emailed to Cas.

Dean took a deep breath and pushed away his anger on Cas' behalf and his worry that even if their ruse worked, Michael would just find another half-baked excuse to keep Cas' kid from him. Cas was stressed enough for both of them. It was Dean's job to help him relax and forget about the world outside the scene. Within the scene, there was no stress or worry because there was no uncertainty. Cas was in complete control for as long as Dean let him be.

~o0o~

While Castiel waited for the water to warm up, the panic that had been held at bay by Dean's warm, familiar maple scent started to creep back in.

What was he thinking agreeing to this? Of course Dean would offer to back up Castiel's lie. He would have done the same for any of his friends in similar circumstances. But it was a miracle that Castiel had made it through five years of friendship and fucking without letting slip that he was head over heels for the sweet, shy, gentle, gorgeous alpha. How was he going to pretend to be almost mated to Dean without hopelessly confusing his inner omega and breaking his own heart?

No, he couldn't do it. He would just have to tell Dean he'd changed his mind…

Except…

Except Castiel couldn't think of another plan with the same chance of success. He and Dean were always getting mistaken for a couple because of how much they hugged, cuddled, and scented each other. (Of course, Castiel did these things because they allowed him to pretend for a few minutes at a time that they were a couple, that Dean was really his alpha. Dean did it because he was a tactile person who just liked cuddling.) It shouldn't be too hard to convince Michael that they were in a relationship and that Dean would be a good alpha role model for Jack. Then Castiel would get his son back, and that was worth a thousand broken hearts.

He took a deep breath and let it out slowly. I can do this. For Jack, I can do this.

He didn't rush his shower. Scening while anxious, scared, angry, or in the grip of any other strong negative emotion was dangerous and irresponsible. He closed his eyes and focused on the feeling of the water hitting his back and imagined that it was washing away all his fury at Michael and all his fears for the future. Instead of Michael's smug, holier-than-thou expression when he told Castiel he couldn't have his son back, he pictured Dean...

Dean fingering himself open in Castiel's bed, filling the room with the smoky, spicy scent of alpha arousal. Castiel's cock quickly grew heavy at the thought, and slick began to trickle from his ass only to be washed away by the water, but he didn't touch himself beyond what was necessary to get clean. He wanted to be able to take his time with Dean, give him as much pleasure as he could stand before finally allowing them both to come.

After almost half an hour under the warm spray, he was completely calm and also completely hard, the thunderstorm scent of his arousal infusing the clouds of steam that filled the bathroom. He turned off the water, dried himself, and dumped his towel and dirty clothes down the laundry chute before walking naked to his bedroom where he was greeted by a sight that was equal parts hot and adorable.

Dean was sitting on the bed, wearing nothing but his glasses, trying unsuccessfully to loop one of Castiel's neckties around his own wrists. "Son of a bitch," he muttered as the slippery silk got away from him, probably not for the first time.

"Would you like some help with that?" Castiel asked, doing his best to keep all traces of amusement from his face and voice.

Dean startled and looked up, a blush tingeing his freckled cheeks. He opened his mouth, closed it again, and then wordlessly held out the tie.

Castiel took it. He knew Dean often had trouble asking for what he wanted, especially when it was the exact opposite of what he'd been taught an alpha was supposed to want, so Castiel didn't insist on a formal request, merely asked, "What is your safe word?"

"Poughkeepsie."

"Are you using it now?"

"No, Omega."

"Would you prefer I tie your hands behind your back or above your head?"

"Over my head please, Omega."

"Then lie down."

Dean obeyed, his head resting on one of Castiel's feather pillows. He had turned down the covers and stacked the extra pillows neatly in the corner even though he hadn't been told to do that. He knew Castiel liked to keep his space orderly, especially during a scene.

Castiel crawled up the bed and straddled Dean's chest. Dean's eyes raked over the omega's body, lingering on the tattoos on Castiel's biceps, black wings fanning out from his shoulder blades to his elbows, before his gaze was irresistibly drawn to the hard cock bobbing right in front of his face, a bead of pre-come welling from the tip. He licked his lips. It was a myth that male omegas had underdeveloped penises. Dean might be a little longer than Castiel, his knot adding on an inch or so, but Castiel was definitely a fully developed adult male, even a little thicker around than Dean, and Dean loved sucking a cock almost as much as he liked getting fucked by one.

Castiel read the desire in Dean's eyes and was sorely tempted to indulge it, but he had a realistic idea of his ability to control himself once he had Dean's mouth on him, so he shook his head regretfully. "Not tonight, Alpha. I need to last long enough to fuck you until you scream."

Dean's pupils, already dilated with lust, blew so wide that only the thinnest ring of green was visible behind his glasses, and a choked moan escaped him.

"Hmmm. You like the sound of that?" Castiel murmured, lifting Dean's hands over his head and beginning to bind them with the necktie, keeping his movements deliberately slow so that Dean could savor the feeling of the silk gliding over his skin.

Dean nodded mutely.

"Yes, it's one of your favorite things, isn't it? Being tied up and fucked until you're begging to come?"

Another nod, this one accompanied by a faint whimper.

Castiel raised an imperious eyebrow. He had let Dean off the hook once already tonight. He couldn't be too lenient. "Say it. Tell me with words or I'll untie you right now and you can take care of that hard on without my help." It wasn't an empty threat, and Dean knew it. Castiel had followed through on it before, much to Dean's chagrin, and Castiel would only wait so long for Dean to work up the courage to speak.

Dean met Castiel's eyes, his cheeks flaming, and said quietly but clearly, "I love being tied up and fucked on your cock. Please fuck me, Omega." There was a defiant tilt to his chin, but Castiel knew it wasn't defiance of his Dom. It was defiance of everyone else, the whole world that had told him all his life that this was the wrong way for an alpha to be, that no 'real alpha' enjoyed getting fucked more than he enjoyed doing the fucking, and certainly no 'real alpha' let an omega tie him up and boss him around.

Castiel gently cupped Dean's cheek, suddenly overwhelmed with so much love for this man. "My good Alpha," he murmured, and Dean shivered under him at the praise. "Test that binding for me."

Dean moved his wrists. "It's good."

"Not too tight?"

"No, Omega. It's comfortable."

"Good. Let me know if that changes." Castiel climbed off Dean's chest and grabbed one of the other pillows. "Lift your hips."

Dean braced his feet on the bed and let Castiel slide the pillow under his lower back. The smoky scent of his arousal mingled with Castiel's own thunderstorm scent like a warm, cozy fireplace on a wild and wet night.

Speaking of wet, Castiel's ass was leaking like a tap, and there was no point letting good slick go to waste just because he wasn't the one getting fucked. Even though Dean had never explicitly said so, Castiel had noticed that the alpha really liked using Castiel's slick in place of artificial lube. He reached back and gathered some on his fingers before testing Dean's entrance.

Dean let out a groan of pure pleasure as Castiel pushed two fingers into him. He had done a pretty thorough job of preparing himself, and Castiel was quickly able to work up to three, then four fingers. The lightest of touches to Dean's prostate had the alpha purring and throwing his head back, exposing the whole column of his throat to the omega in the ultimate sign of submission.

This was Castiel's favorite thing about sex with Dean; he had the privilege of witnessing that moment when Dean let go of all those preconceptions about alpha-ness and just obeyed his instincts, becoming truly himself. "There you are," Castiel whispered, leaning down to lick a stripe from Dean's jugular to his scent gland. "My good, beautiful Alpha."

He gathered more of his slick to lube up his cock and finally entered Dean. As sappy as it sounded, even in his head, it really was like coming home. He had been with a few female omegas and one male beta who let him top sometimes, but it had never felt this right, this perfect. Dean was so responsive, so beautifully loud. He rarely used words during sex unless Castiel demanded it, but he keened, and moaned, and gasped with every thrust. His hands twisted relentlessly in the bindings, not trying to escape, just feeling them, reminding himself that they were there.

As soon as he felt Dean start to tense up around him, winding tight with his building climax, Castiel stopped and pulled out. Dean gave a frustrated whine, but didn't complain when he realized he wasn't going to get to come yet. "Color?" Castiel asked breathlessly.

"Green."

Castiel smiled and rewarded him with a lick to his scent gland. When he was sure that Dean wasn't on the edge anymore, he added more slick and pushed inside again. Shallow, gentle thrusts at first, working up to a faster rhythm, and stopping as soon as the tension in Dean's muscles and the strength of Dean's scent let him know the alpha was close.

Each time he checked in with Dean, and each time Dean gave him permission to keep going until after the fifth time he edged Dean, the response was a hesitant, "… yellow."

"What's wrong?" Castiel asked. "Is it starting to hurt?"

"Yeah. I think I almost popped a knot that time."

"Okay. Thank you for telling me, Alpha. You can come this time. Whenever you're ready." Castiel wasn't sure he could have lasted much longer himself anyway.

He re-slicked his cock one more time. When he pushed back into Dean, the alpha gave a contented sigh, completely surrendering to the pleasure now that he knew he didn't have to hold back or control himself anymore.

Castiel still took it slow, coaxing Dean gently toward climax, but as they both drew closer, his movements inevitably became faster and less coordinated. Dean was making breathless uh and ah noises every time Castiel punched into his prostate, getting louder and louder, and then he did indeed scream, his back arching off the bed as he painted his chest white. His knot popped completely untouched, and Castiel reached down to squeeze it, milking a second orgasm from him that was even more violent than the first.

With Dean writhing and moaning and coming over and over beneath him, all Castiel really had to do was stop trying not to come. His vision whited out as he finally allowed himself the blessed relief of spilling inside Dean.

When he came back to himself, Dean was gazing hazily up at him, clearly high on endorphins. With trembling fingers Castiel unbound Dean's hands. He also removed Dean's glasses and laid them carefully on the nightstand, before laying down and gathering the alpha into his arms to cuddle and scent and lick him while they came out of the scene. He made no attempt to clean them up. Being covered in each other's come, the most primal form of scent marking, would help keep them from dropping.

About half an hour passed before Dean came back to himself. Castiel could tell when he was becoming aware again because his hand which had been laying limply on Castiel's arm began to move, deliberately tracing the lines of Castiel's tattoos. "Are you back with me, Dean?" Castiel asked, using his name instead of Alpha to signal that the scene was over.

Dean made a noise halfway between a sigh and a purr. "Yeah. Just don't ask me to stand up any time soon. Legs feel like jelly."

Castiel chuckled. "I imagine you'll have some trouble sitting comfortably tomorrow as well."

"You don't have to sound so smug about it," Dean muttered, but there was no rancor behind the words.

"Thank you, Dean," Castiel whispered, stroking the alpha's sweaty hair.

Dean huffed a laugh into Castiel's shoulder. "You don't have to thank me for sex, Cas."

"Not just for the sex. For everything. For helping me get my son back. For being…" His heart broke a little to say it, but he knew it was the truth. "For being a good friend."

Dean was quiet for a minute, and Castiel would have thought he had fallen asleep if his hand hadn't still been moving, lightly tracing the ink feathers on Castiel's right arm repeatedly. Finally he murmured, "Don't have to thank me for that either."

Castiel decided that aftercare was not a good time for a discussion of Dean's sometimes excessive selflessness, so he let it go.

It was Dean who next broke the silence. "You know, if we're gonna sell the whole almost mated thing, you should probably have a claiming bite."

Castiel couldn't help tensing up a little. The alpha he was desperately in love with offering to claim him while they were laying in bed together, sweaty and satisfied and covered in each other's scent? Yeah, no amount of logic would convince his inner omega that that was just Dean being a good friend.

Dean mistook his tension for discomfort at the idea of Dean biting him and quickly said, "We don't have to. We could fake it with makeup or something."

"No. It's better if it's real. We don't want to give them any reason to doubt our story. Do you want to do it now?"

Dean lifted his head to look at Castiel. "You're sure?"

Castiel closed his eyes, an indescribable feeling, not quite happy and not quite sad, filling his chest. "I'm sure. It's just… not how I imagined it. You know?"

No, he had imagined that a claiming bite from Dean would be followed by a mating bite from Dean, and that both would be because the alpha had fallen as deeply in love with him as he had with Dean.

"I know," Dean said softly, though Castiel was quite sure he didn't. "You can still have that someday, Cas. When you… when you meet the right person."

Castiel didn't think he could take much more of this conversation without blurting out the truth, so without opening his eyes, he tilted his head to the side, baring his scent gland to Dean in a silent invitation.

"Okay. I'll, um… I'll try to be gentle."

"Not too gentle. It has to leave a mark."

He felt Dean lean in, felt the alpha's teeth scrape his neck, and guiltily allowed himself to pretend that all his dreams had somehow come true.