It had just been a shit day for Castiel.

His doctor's appointment had been a joke. His wrist was throbbing. He knew he should have presented by now, he didn't need some specialist looking down their nose at him and telling him in such a patronizing tone that he 'shouldn't worry yet' that it was unlikely that he was a sterile Unpresented.

Cas knew better.

He was nearly thirty, and most normally presented between fourteen and twenty. He was almost ten years past that, and long past hope.

The new cast on his wrist itched. It was the wrist that had taken him to the doctor in the first place. Slipping on a patch of ice that morning on his way out to his car, Cas had landed hard, catching himself with it. He knew it was broken before his entire body hit the ground; he heard the bones snap.

Cas had sat in the doctor's office for nearly two hours waiting to get x-rays, and nearly twice as long to get the cast. The paperwork he'd had to fill out required him to disclose his presentation status. When he had checked the 'unpresented' box, the doctor had questioned him invasively about it, insisting that he not be released until he had seen the specialist. Blood was drawn, tests were run, and Cas received the exact same answer he had gotten for the last ten years: 'it's not too late', 'give it more time', 'any day now, I'm sure'. He was sick of it. Sick of it all.

And now Cas was standing on the side of the road, in the sleet, with a flat tire. One he couldn't even change himself with the stupid cast on his wrist.

Great.

Just great.

All he wanted to do was go home and curl up under a blanket and shut out the world for the rest of the week. He was irritated, he was uncomfortable, and he knew he only had one choice. Cas pulled out his phone and dialed.

"Hello, Dean," his low voice grumbled into the phone.

"Heya, Cas," Dean answered. Cas could hear the smile in his best friend's voice and it made his mood drop more. "What's up?" Cas looked above him.

"Sleet," he said flatly, "but it's coming down rather quickly." There was a moment of silence before Dean spoke again. The amusement clear in his voice.

"Yeah, I got that, Cas. I meant what are you up to? What are you calling about?"

"Oh," Cas' brow furrowed farther, "yes, of course. Uh...I-..I need some help."

"What's wrong?" Just like that, the humor was gone from Dean's voice, replaced with genuine concern.

"Well," Cas began, "I have a flat tire, and I can't change it with this cast on my wrist-"

"The hell, Cas?!" Dean nearly shouted, "why do you have a cast on your wrist?!"

"I fell this morning and broke it," Cas said, as though it should have been obvious.

"And you didn't bother to call THEN?! Jesus, Cas!"

"Dean," Cas was so done with today. His arm itched, his clothes were getting wet, and that urge to go home and curl up was growing with each passing minute. "Could you please come help me change my flat tire?"

"We're on our way, Cas," Dean said. Cas could hear the rustling of fabric and the sound of Dean's keys as he shouted to his brother on the other end of the line. "Where are you right now?" Cas gave Dean his location, and climbed back in his car to try to stay warm and dry. "Sammy and I'll be there in ten minutes. Just stay put." Dean hung up the phone.

"Where else would I go?" Cas said to the silent phone in his hand.

Cars sped by, none of them stopping to help or inquire about him, leaving Cas to his solitude. Cas' irritation and discomfort grew with each set of headlights that zipped past. He loosened his collar and tie; they were suddenly too tight. The fabric against his skin felt like sandpaper – worse where it was wet. He rubbed his good hand across his face. Cas picked up his phone again and called in to work. He let them know that he would not be in today. It was already past one, and he couldn't stand the thought of being around people.

At least, not those people.

Dean was on his way. Dean would help him. Dean would understand the need to not be at work and wouldn't judge him for it. Sam would understand, too. Maybe.

Cas both thrilled and dreaded the arrival of his best friend. The strong, hard-bodied alpha always made Cas feel safe. Protected. But more than that, he made Cas feel stronger. Dean had presented young, when they were still pre-teens. Cas had always thought that, if circumstances worked out, he would want to mate someone like Dean. Someone who would take him with all his quirks and lack of understanding of pop culture references.

But things just didn't work out that way for Castiel.

He was an Unpresented. He was sure of it. No one would ever mate him. Why would they? Cas was sterile. 'Defective'. Of no use.

Cas' face was wet. He wiped his good hand down it again, and startled when someone rapped on the driver's side window.

Opening the door, Cas stepped out of the Car. He flushed at Dean having caught him in the middle of such an awkward and painful thought. Cas was hot with embarrassment. Dean's brow raised as he took in Cas' appearance.

"You okay, buddy?" Dean reached out a hand to Cas' shoulder. Cas choked on a noise; half sob, half laugh. Before he could think better of it, Dean pulled Cas in for a firm hug. It was quick, and almost brotherly, but it was enough.

Then Cas felt it.

Hot and wet, he felt it leak from him the instant Dean's skin touched his.

Dean pulled back and turned toward the flat, driver's side, rear tire.

"Go ahead and pop the trunk, Cas," Dean said to him. "Me and Sammy'll have this done in a jiff-" Dean looked up at Cas as Sam made his way around to the trunk. "Cas?" Dean said, once again concerned. Cas hadn't moved. He was in shock.

"Cas," Sam asked, "you okay?" Dean's gaze flicked from Cas to Sam, and he moved back to where his best friend stood in the crook of the open car door.

Cas could feel the slick seeping from him. He was presenting. Now. As an Omega. At Dean's touch. He couldn't focus. He knew Sam and Dean were both there, that people were speaking to him, but he couldn't hear any of it over the rushing in his ears.

Suddenly, Dean was standing in front of him, reaching past him to pop the trunk. Cas noticed Sam start to work on the tire, but was distracted the instant Dean's hands gripped his upper arms. Dean shook him gently.

"Cas," he said firmly, maneuvering him to sit down on the driver's seat, "hey, you in there?" He dropped into the seat with a huff, feeling the slick spread further. Dean squatted down in front of Cas, trying to bring Cas back to reality.

It was then that reality hit Dean.

The sweet, honey and spice scent of Cas' first heat hit Dean like a mac truck and his body went rigid. A low, rumbling growl purred from his chest, and Cas' eyes found his. Brought back to the present by the possessive sound. A whimpered sigh fell from Cas' parted lips, and a fresh wave of slick rushed from him.

"Sam," Dean roared at his brother, Alpha instincts taking over, "you'd better hurry the fuck up." Sam rolled his eyes at his older brother.

"Ya know," he said, pushing his damp hair out of his face, "this would go a lot faster if you gave me a hand."

"Can't." Dean's curt answer made Sam stop what he was doing and look up. One look at the two men was enough to know what was happening. Dean turned a challenging eye on Sam, who raised his hands in surrender.

"Go," Sam said, "I got this."

Dean hauled Cas out of his car and manhandled him into the Impala, growling at Sam as they passed. Level-headed little brother or not, Sam was still an Alpha, and therefore, still a challenge to Dean. Dean knew he needed to keep himself in check. This was Cas. His best friend. He wouldn't take advantage of his situation, no matter how badly he wanted Cas. Had always wanted Cas.

The engine roared to life and Dean and Cas peeled away from the curb, heading for Cas' house.

Surrounded by the scent of leather and Dean, embedded into the very fibers of the car, Cas felt his heat flare. He slumped in the seat, feeling himself soaking through a layer of clothing at a time.

"Deeeaan..." Cas groaned.

"I know, Cas," Dean crooned, "I got you." He clapped one hand on Castiel's shoulder. His other hand clenched the steering wheel tighter. They needed to be to Cas' place NOW. "Almost there."

Cas' eyes were glazed and heavy when they finally pulled in the driveway.

"Dean," Cas was shaking as he tried to pull himself up in the seat and out of the big, black car.

"Hang on, buddy," Dean said as he slipped out and jogged to the passenger door to help Cas out. An arm around his waist, Dean hoisted Cas to his feet. They made their way toward the door. Cas was torn between leaning in and breathing deeply the scent of the Alpha and running away from the man he knew he could never have.

Dean was destined to mate some perky little Omega with big boobs and long hair. Castiel would stand by and watch his best friend live the apple-pie life he deserved. It didn't matter that there was nothing in the entire world that Cas wanted more, that Dean was all he had wanted since he was twelve, he wasn't good enough for Dean. He deserved better than Castiel.

"Cas," Dean's voice sounded strained, "where're your keys, man." Cas patted his pockets. Realization dawned on him.

"I...I left them in the car," Cas swallowed hard. Dean looked at him, raising an eyebrow.

"Okay then," Dean said. He propped Cas up against the door frame and reached up into the porch light to pull down the spare key. He made quick work of opening the door and replacing the key, glancing sidelong at Cas as he did. "Let's go, tiger." Dean grabbed Cas' arm and threw it over his shoulder. Dean's body went rigid again as the scent of fresh slick reached his nostrils.

"Deeeann..." Cas pressed himself closer, unable to resist.

"I know, man. Come on," Dean nearly carried Cas through the door and up the stairs to his room. He set Cas down on the edge of the bed.

"Dean," Cas licked his dry lips, "Dean, I'm so thirsty."

"We'll get you taken care of, Cas. Hang in there." Dean reached forward to Cas' swaying frame and began to loosen the tie at his neck. His hands brushed across the bare skin above the collar. Cas gasped at the touch, another wave of slick pulsing from him. Dean jumped back. When Cas met his eyes, the pupils were blown so wide hardly any of that gorgeous green he knew was there showed. "You should...uh...get outta those wet clothes." Cas didn't miss how Dean's voice faltered on that one word. Wet. Cas was wet. Very wet. Not just from the sleet.

Eyes locked on the man standing over him, Cas slid his trench coat off his shoulders along with his suit coat. Both caught on his cast, and he shook himself free of them. He yanked at his tie until Dean stepped in again to help him. Dean's hands trembled as he fumbled with the buttons on Cas' shirt, and his tongue slipped out to wet his bottom lip.

"I'll..." he swallowed hard and cleared his throat, "I'll be right back, Cas. You, uh...you get into something...comfortable." Dean wiped a hand down his face as he turned and moved toward the door, pulling his phone out.

Cas' breath turned panting. He felt a physical pain when Dean left the room, and had an urge to follow him. But his Alpha had told him to change.

No.

Not HIS Alpha.

Cas pushed the thought from his addled brain and stumbled to his dresser. He pulled out a pair of loose fitting boxers and made his way back to his bed, dropping them on the floor next to his nightstand. He threw the covers back and climbed onto the bed once more. It was all he could manage for the moment.

Dean slipped back downstairs as his brother answered the other end of the line.

"Sammy," Dean huffed. "Need a favor."

"Everything okay?" Sam asked, genuine concern laced with a touch of amusement. Dean sidestepped the question.

"Listen, need you to pick up some stuff for Cas. I don't think he can be alone right now. Pick up some Gatorade, some protein bars, some of those old-people nutrition drinks, and...uh..." Dean trailed off.

"And?" Sam pressed.

"Some, uh, some lube and...a knot." Dean rushed.

"A knot?" Sam was incredulous.

"Yeah, Sam," Dean growled at his brother, "a knot. It's Cas' first heat, and he's gonna need some help getting through it, so yes. A knot. And don't get the cheapest one you can find. Get him a decent one, will ya? It's Cas." Dean hung up before Sam could say anything more.

"Deeeaaaannn..." The sound of Cas so needy made Dean's blood rush hot through his veins. He took a deep breath, tamping down every urge his body had. His friend was in need.

"I'm commin', Cas," Dean called up the stairs. "I'll be up in just a few." He looked around Cas' kitchen. Filling a glass of water, Dean headed back toward Cas. "Sam's on his way with some stuff for you, Cas," he said as he mounted the stairs. "I know it's not ideal, but it's the best we can do for right-" Dean froze in the doorway. He gripped the glass in his hand so hard he was sure he heard it crack.

Cas was laying on his bed, naked from the waist up, his slacks pushed down his thighs, and his erection straining against his plain white boxers underneath. A wet spot of leaking precum making them almost see-through. One hand had disappeared below the waistband of Cas' boxers, and his hips thrust up seeking any sort of friction they could find.

Dean couldn't move. He couldn't. If he did, he knew he would risk ruining his friendship with Cas. He wouldn't do that. And then Cas said it again.

"Deeeaaannn..." The name spilled from Cas' mouth on a moan. Dean's instincts took over and he was next to the bed in an instant.

'No. No, no, NO!' Dean told himself. He took a shaking step back and set the full glass of water on the nightstand. The scent of Omega slick and heat was overpowering, making him dizzy. Dean moved to the window and opened it wide, gulping in the fresh air. He gripped the sill, panting in the cold, winter breeze. He looked up and saw a jogger on the sidewalk pause as the scent of Cas hit him. The slender, blonde haired man with perfect teeth looked around for the origin of the intoxicating scent, going rigid when he located the source. The possessive Alpha in Dean took over before he could stop it.

"Keep walkin', asshat!" Dean shouted at him. Dean's lip curled back and a low rumble tore from him. Maybe the open window was a bad idea. Dean slammed it shut.

"Oh, god, Deeeaan!" Cas groaned, his knees shaking with need. At the sound of his name, Dean whipped around to the man who needed him.

Not HIM.

Just...needed.

"Dean, please," Cas panted. Steeling himself, Dean stepped to the bed and pulled Cas' slacks off completely. He hesitated for a moment, his hands hovering over the waistband of Cas' boxers. Dean didn't know the etiquette for this. But Cas needed him. Needed his HELP. "Dean, I need you." His resolve was crumbling. Cas grabbed Dean's wrist with his casted hand. Again, Dean froze.

"I know, Cas. I'm right here. We'll get you through this, just hang on. Sammy'll be here soon, and then you'll be good."

"Dean?" The sound of his younger brother shouting for him from downstairs broke Dean from his trance. He patted Cas' hand, pulling his wrist free, and forced himself from the room. He pulled the door shut behind him, and raced down the stairs to block the sound of Cas' piteous whimpers from his ears.

Sam's gaze traveled over Dean's flushed and mussed appearance. He caught the strong scent of Cas on Dean and coughed pointedly. He held up a set of grocery bags.

"Here's your supplies," Sam smirked. "Swap me keys. I'll take the Impala home." He pulled Cas' keys from his pocket and held them out for Dean. It took Dean's brain a moment to catch up.

"Uh, yeah, yeah. Here," Dean tossed his keys to Sam as he began pulling items from the grocery bags. He set the items on the table, taking stock of the things he had asked for. "Sammy, I'm gonna need you to take over things at the garage for the next few days. Schedule should be set, but check with Charlie. Bobby, Benny and Ash should be able to cover the stuff we've got booked this week. I'm not sure if-," he paused, searching through the bags again, then turned a confused glare on his younger brother, "where's the rest of it? I told you to get Cas a knot!" Sam looked at him flatly. "Damn it, Sammy, he's gonna need one!"

"Yeah," Sam said, raising his brows. "He is."

"Then what the hell, Sam?" Dean was nearly shouting.

"Dean," Sam rolled his eyes, as he turned and headed out the door, "you're an idiot."

"Sammy," Dean growled, as Sam turned and headed for the door. "Cas needs a knot! How the hell is he supposed to get through this without one? He needs, it, man!"

"Yeah," Sam tossed over his shoulder, "he does." With that, he closed the door behind him, not even sparing a glance at his brother as he left. Dean was speechless.

"Deeeaaan!" He turned at his name.

Shit. Shit. Shit.

Dean was stuck now. No other options. He knew Cas needed this, but did he WANT it? He took the stairs slowly. He paused, his hand on the door. He could hear Cas' low moans, his panting breath. Dean swallowed hard and opened the door.

There was Cas laid out like a feast for him.

Fully naked now, Dean watched as Cas fingered his sweet, wet hole. The arm with the cast thrown up over his head, Cas' face turned toward it.

"Fuck," Dean breathed. He was hard in an instant.

Cas was sure his skin was on fire. Certain that at any moment, he would combust. He couldn't hold back any more. He knew Dean would never want him, but right now Cas needed him. He would let the guilt and worry take over him when the heat receded.

He reached out for Dean. His flushed body trembling with hope that Dean wouldn't turn around and leave him again. He watched something in Dean's expression change and let out a sigh of relief as Dean stepped toward him.

"Cas...I- I don't...," Dean choked on his words. Cas watched his Adam's apple bob up and down as Dean swallowed hard.

"Please, Dean," Cas whispered. "I know. I know you don't want this, but..." Cas turned his eyes away from him, not wanting to see disgust – or worse – in Dean's face, "I need you."

"Cas," Dean took another step toward the bed. "That's not-...I didn't mean-...," he ran a hand through his hair. How would he explain that that was the exact opposite of what he felt? He didn't do feelings, or words, very well. So he did what he knew best.

Cas watched as Dean peeled his flannel off, stepping closer to the bed. His heart hammered in his chest and he felt the slick rush from him again. His fingers still buried inside himself, Cas' breath hitched at the warm sensation. Dean sat down on the edge of the bed slowly, tentatively, as though Cas would startle if he moved too fast.

Slowly, gently, Dean lifted his hand. He held it, hovering, over Cas' stomach, watching as the muscles shifted and trembled just out of contact.

"Cas," Dean pleaded, locking eyes with the man writhing below him. "Please...please don't hate me when this is over." Cas' movements stopped. His breathing hung heavy in the air.

"I could never hate you, Dean," Cas' brow furrowed with worry. His brain was just shy of being obliterated. He reached up to Dean's face, his fingers feverish and the cast cool. Dean turned into the touch, his eyes slipping closed. "Please, Dean. I want this."

Dean's eyes flew open.

Did he just hear that right?

"Dean, I want to know what it feels like."

Just like that, Dean was thrown into a memory. One he kept locked away.

He was twelve. His best friend, Cas, had spent the night. Dean woke on his stomach, rutting into the mattress, a needy heat low in his belly. He turned panicked eyes to Cas, lying next to him on the bed.

Blue eyes met green. Dean noticed the flush high on his best friend's cheeks.

"Cas," Dean sounded as worried as he looked, "I-I think it's happening." He pulled his hands up to either side of his head, fisting the sheets. Cas nodded at him.

"It's okay, Dean," Cas tried to reassure him. He slid one hand under Dean's and squeezed. "It's okay." Dean turned his face into the mattress, his hips thrusting hard. "What...," Cas swallowed, "what does it feel like?" he whispered to Dean.

"It's...it's like something is pulling inside me," Dean panted. "Like I need more. It almost hurts, but it feels so good, too. It's...swollen, and it's really sensitive. It feels like...like I'm gonna explode." Dean kept rutting, squeezing Cas' hand harder.

"I want to know what it feels like."

"You will, Cas," Dean huffed, "I'm sure you'll know soon, too."

Cas turned his face away as, with a sigh, Dean pressed into the mattress one last time.

Dean's eyes went wide with realization. He cock gave a throbbing pulse.

"Shit, Cas!" Dean wrapped his hand around Cas' pressed against his cheek. "You've said that to me before." Dean pressed his free hand against Cas' chest and felt his heart hammering against his ribs. Cas's eyes went wide as he nodded. Dean licked his lips and leaned forward over Cas' face. "Shit Cas!" Dean moaned, "You didn't mean you want to know what it's like to HAVE a knot, you meant you wanted to TAKE a knot, didn't you?!"

Cas' breath stuttered as the word 'knot' fell from Dean's lips. He shook his head.

"Not just A knot," Cas whispered. There was no going back now. His Alpha was touching him. "YOUR knot, Dean." In for a penny, in for a pound. "You could have had me then, if you'd wanted." He rocked up, begging for Dean's touch to spread across his body. "Always been yours, Dean. Even if you don't want me, I don't care. I'll always be yours."

Dean was sure he was hallucinating. Did he hear that right? This gorgeous Omega, his best friend, one of two people in the world Dean would gladly give his life for wanted him? HIM? He felt Cas' breath ghosting across his lips. Without a word, he surged forward, claiming those lips with all the fervor of need and want that raged within him, longing to claim the Omega for his own.

Cas arched up into the touch in bliss, anguishing for more. Dean licked across Cas' lips, begging for entrance. Willingly, Cas opened up to the man he had pined for all his life. Their tongues working to explore the words that could not be spoken. He gripped at Dean's t-shirt as best he could with both hands, nearly tearing it from his body. Dean made quick work of his jeans, kicking his boots off at the same time.

Their mouths still joined, tongues seeking, prodding, caressing, Dean climbed over Cas' body. The heat rolling off him enough to send goosebumps shivering down Dean's skin.

"God, Cas!" Dean breathed into his mouth, "you deserve better than this." He shook his head, burying his face in the crook of Cas' neck, breathing in his intoxicating scent as deeply as his lungs would allow. Soaking in what he was sure would be his only chance to feel Cas like this, he sighed. "You deserve better than me. You don't want me."

Cas' grip on Dean's arm was like a searing brand. Dean pulled back, shocked, to look down at the hard gaze burning in Cas' eyes.

"Don't you dare presume to know what I want," his voice growled out of him like thunder. "I have wanted you for as long as I can remember. I'm the one who doesn't deserve you."

"Cas-" Dean tried, but Cas cut him off.

"No, Dean," his voice and body shook with anguished need. Dean huffed, looking away from Cas. "Dean, why would you want me?" His voice was small, timid, "chances are, I'll never be able to give you the things you want. Things you should have. Things you deserve."

Dean was done with this.

He had had enough of talking. They could sort this out later. Right now he wanted, and Cas needed. Pulling his boxer briefs off, Dean settled himself between Cas' legs, pressing their erections together.

Cas cried out at the sensation, and Dean swallowed the sound greedily. Running his hand down Cas' sweat soaked skin, Dean trailed his fingers down to feel the pooling wetness leaking freely from Cas. He ran his fingers up and down the cleft of the Omega's firm ass, his cock throbbing at the mewling noise he stroked from Cas.

"That's it, Cas," Dean whispered against his lips, "so wet for me, aren't you?" Cas groaned, throwing his head back and exposing the long, flushed length of his throat for Dean to claim with teeth and tongue. It was too much temptation for Dean. He pushed himself up, away from the enticing stretch of Cas' body. He gazed down in wonder at it.

Flushed and shimmering in a layer of sweat, Cas arched up, chasing the touch of Dean's body against his own. Dean sat back on his heels, tossing both of Cas' legs to one side.

Cas' body knew what it wanted. What Dean wanted.

In an instant, Cas was on his knees, arms stretched out, cast bumping the wall, chest pressed into the mattress, presenting himself to Dean. His hips rocked back and forth ever so slightly, begging for Dean. A groan fell from Dean as he watched a pulse of slick slip from Cas, wetting his hole and running down to drip from his balls.

Dean watched, in awe, the sight before him. He moved his hands up to Cas' thighs, terrified that this vision would melt away the moment he touched it. His hands made contact with the warmth of Castiel's skin, and he slid his hands up to Cas' cheeks.

Cas spread himself wide for Dean, moaning and panting into the sheets. Drawn forward as if by a force outside himself, Dean pressed his lips to Cas' delicate hole. Slipping his tongue out, Dean licked across the entrance. It was like an electric shock to both of them. Cas gasped, his body going rigid for a moment, then relaxing as a wave of slick rushed from him. Dean groaned again as he felt it spill across his tongue and lips, dripping down his stubbled chin. It was delicious. Dean had never tasted anything so wonderful in his life. It was better than pie.

Cas' reaction was addicting. Dean wanted more.

He pressed the flat of his tongue against Cas' hole and licked again. This time Cas cried out, shuddering at the sensation.

"You like that, baby?" Dean crooned against Cas' hole. "Like the feel of my tongue against that tight little hole of yours?" Cas was beyond the use of words. He pressed back, seeking Dean's tongue again. "So eager for me!" Dean gripped Cas' hips in a bruising hold and licked into him. He breached Cas with the tip of his tongue, massaging and coaxing inhuman sounds out of him. When Cas would release a rush of slick, Dean would suck it down eagerly, desperately.

Cas' legs shook violently, threatening to give out underneath him. Dean didn't want to rush, knowing this was Cas' first experience, and knowing this might be his only chance at this. But he knew Cas needed more, and his Alpha instincts were starting to get the better of him.

Dean slid a finger in alongside his tongue. The slick from Cas more than enough lubrication, Dean pressed his finger in to the third knuckle.

"Dean! Oh, god! Dean!" Cas bucked back against him. Dean dragged his finger in and out slowly, gently. "Mmmm! Yes! Fuck, that feels so good! Please don't stop," Cas begged and rocked, shaking and sweaty. Dean slid a second finger in and Cas gasped, clenching around the intrusion.

"Easy, there, angel," Dean chuckled, his breath hot against Cas' hole. "You gotta relax, baby." Cas did his best to loosen his muscles as Dean worked his fingers, scissoring and stretching Cas wider.

By the time he had worked three fingers in along with his tongue, Cas was a writhing, incoherent mess and Dean was shaking with the effort to hold back his own need. The only words Dean was able to understand were 'more', 'please' and 'Dean'. His hand was soaked past the wrist with Cas' sweet slick, and he couldn't get enough of it.

"Fuck, Cas! Just look at you! Dripping for me...Oh, god, Cas, I've wanted to see you like this forever!" He crawled up Cas' back, kissing and licking the beautiful expanse of skin as he went. "You ready for me, baby?" He whispered in Cas' ear. Cas nodded vigorously, trying to fuck himself back onto Dean. "No, angel," Dean growled. "Not like this." He sat back on his heels, pulling his fingers out, and Cas whimpered at the loss of contact. "Wanna see you, baby," Dean soothed. He placed his hands on Cas' hips and gently rolled him onto his back. His Alpha instincts were screaming at him to take, take, take, but he wouldn't do that. Not to Cas.

Dean lifted Cas' legs, pressing his knees toward his chest, and lined himself up with Cas' entrance, stroking his aching cock with the hand covered in Cas' slick. He hovered there a moment. There would be no coming back from this. Things would be weird between them if he were to stop now, but would they break if he kept going? Was that a risk he was willing to take? As if Cas could read Dean's thoughts, he spoke.

"Please, Dean. I want you. I've always wanted you."

Dean pressed himself inside, bottoming out slowly. The heat and intense pressure took his breath away. He wouldn't last long like this.

Cas arched up at the feeling of being breached by Dean's cock. He could feel it throbbing deep inside him. Finally, Cas felt whole. When Dean was fully seated in him, they both paused to catch their breath. Cas clutched at Dean, willing him to come closer, and Dean seemed just as eager to get closer to Cas. Wrapping his arms around Dean's back, Cas clawed at him as Dean began to rock in and out.

"Deeeaan!" Cas moaned. It was exquisite. The burning pleasure, the scent, the hot, wet slide of skin. Cas never wanted it to end, and yet he was desperate for something more.

"Oh, god, Cas!" Dean cried out, "I wanna feel you cum! Wanna feel you clench around my knot." Cas gasped. That's what he wanted. What he NEEDED – Dean's knot.

"Knot me!" he screamed, head thrown back, body arching. "Oh, Dean, claim me!"

A searing heat shot down Dean's spine. Is that what Cas really wanted? He wrapped his arms under Cas and slammed into him, hitting his prostate and drawing shuddering gasps and beautiful cries from him.

"That what you want, angel?" He growled against Cas, feeling him shiver in his grasp as he continued pounding into him, hitting that same sweet spot. He felt his knot begin to swell, and he punctuated each thrust with low, rumbled questions. "Want me to fuck you?" Cas moaned. "Knot you?" He clutched at Dean. "Mate you?" Cas gasped, turning his head to the side and presenting his neck to Dean. Dean dragged his teeth across the flawless skin there, lapping at Cas' pulse point. "Claim you?" Cas cried out wordlessly at that, and Dean's knot began to catch at his sensitive rim. The last thread holding Dean's Alpha instinct back broke and the animal within him took over. "Breed you?"

"Dean, yes!" Cas' voice broke from him. "Fuck me full! Breed me full of your pups! Oh, god, please! Please! Please!" Cas thrust against him, cumming hard between them and clenching down on Dean as his orgasm tore through his body.

It was over for Dean. He heard himself growl 'mine' as he sank his teeth deep into Cas' neck. As his knot finally caught, he pumped his seed deep inside the slick, tight hole of his best friend.

His lover.

His mate.

Cas cried out in ecstasy, gripping Dean by the hair and holding him in the bite.

"Yours!" Cas shouted. Dean felt another pulse of cum pour into Cas at the words, and he licked over the wound he'd made, pressing gentle kisses to every inch of Cas he could reach.

At long last, Dean felt Cas go limp below him, his arms and legs sliding off of Dean's body. Trying not to move too much, Dean pressed himself up enough to look Cas in the eye.

"Cas,...I..." Dean furrowed his brow at those wide, innocent, blue eyes. He swallowed hard. "Why didn't you ever tell me?" Cas looked away. There was nowhere to go, though. They were tied together. Figuratively and literally.

"Because I-...I was an Unpresented. Or, at least, I thought I was. Until today." Cas turned his gaze back to Dean. "Why would you ever want to mate with that?" Dean saw the sorrow and the years of hidden hurt behind those eyes.

"You should have told me, Cas," Dean brushed his nose against Cas'. "Too late now, I guess," he chuckled as he settled in on Cas, burying his face in the warmth of his neck and pulling him closer. "You're stuck with me now." Cas hummed as he wrapped his arms up around Dean, careful not to scratch him with his cast.

"Dean?" Cas asked around a yawn.

"Hmm?"

"I'm glad I know what it feels like now. I like it. A lot." Cas felt Dean smile against him.

"Me too."