Disclaimer: I don't own SPN.
Based off a Tumblr headcanon I found on Facebook :)
It was all Cas' fault, Dean decided. If Cas hadn't wanted to watch that stupid soap opera then none of this would have happened!
"Why does James give Nicole a ring when he asks her to marry him?" Cas frowned as the overly tearful woman shared a passionate kiss with the handsome man on TV.
"Because he loves her," Dean shrugged. He shifted so that he could pull Cas into a tighter embrace and rest his chin on the angel's dark hair. "Or she's just ten years younger than him and ten times hotter and this is a damn soap. Take your pick."
"But I don't understand. Why must James prove his love to Nicole by presenting her with an overly encrusted band of metal?" Cas persisted. "How could a material possession possibly compare to the love he feels for her in his heart?"
"It's just a custom, okay, Cas?" Dean said. "Humans give each other rings to tell other people 'hands off, this one's mine'. That way other people won't hit on them – usually – and it's a way for a couple to feel bonded."
Cas frowned thoughtfully.
The next day, Dean was mortified when Cas appeared next to him and Sam in the parking lot and immediately bent down on one knee.
"Cas! What are you doing?" Dean hissed. People were beginning to stare!
"I confess that I am not aware of most human customs," Cas said. "But I feel that I have a satisfactory grasp of this one."
Dean narrowed his eyes suspiciously. Cas wasn't really going to, was he?
"I have loved you since the moment I pulled you out of perdition," Cas continued. "My only regret is that it took us so long to realise exactly how we felt about each other. I wish to feel bonded with you, Dean, and to tell people 'hands off, this human is mine'."
Cas pulled a packet out of his pocket and ripped it open to reveal a massive red candy ring.
"I did not have the funds to purchase a proper ring," he said regretfully. "But I feel that this token accurately conveys my message. Dean Winchester, will you be mine and no one else's?"
Dean was frozen in place. He was hyper aware of the crowd that had formed around them was watching them intently and a few people were – to his horror – cooing over the adorableness of it all! Sam was watching them with a giant smirk on his stupid moose face. But honestly, Dean was touched that Cas had gone to this effort, even if the ring would probably be gone by tomorrow, and he rather liked the idea of belonging to Cas and of Cas being his in return.
"I – yeah, sure," he croaked. "Sure I will, Cas."
Cas' face lit up in one of his rare smiles and Dean let him slide the ring onto his finger in a move that could only have been picked up from soaps. The crowd around them started to clap and cheer and though Dean could hear a few people muttering about the filthiness of it all, he found that it was oddly easy to tune those people out.
"Come on." Sam was still wearing his moose smirk. "Get in the car, lovebirds. Cas can suck on you now in public, Dean."
Dean wondered if it was possible to kill someone purely by trying to shoot daggers out of one's eyes.
-oOoOo-
Dean was about ready to kill Sam. In the space of two hours, he had made no less than fifty references to Dean's new ring and Dean was beginning to wonder if he could shoot Sam and get away with it by claiming that he'd been moose hunting.
"You know, it's legal in nine states now," Sam said casually though he was smirking. "It'd be easy next time we're in Maine…"
"Can you quit it?" Dean snapped. "I – it doesn't even make sense!"
"But Dean," Cas said with a sad, confused frown. "You said you would be mine. And I am yours. Why are you opposed to this idea?"
"Because – well – there's just no point to it!" Dean said. "We stay in awful, crummy motel rooms every night and live out of Baby the rest of the time! It's not like Cas and I'll ever have to file for taxes together or something, since neither of us have a job or a house or anything."
"What about if you're in hospital?" Sam challenged. "Only family members can visit, you know."
"I'd like to see someone try and keep Cas away," Dean said simply.
"Dean does have a point," Cas said slowly. "As far as the United States government is concerned, I do not exist. And Jimmy is listed as a missing man, not to mention that he was married himself."
"Exactly," Dean said, glad that Cas was taking his side. "It'd be a bit hard to apply for a marriage licence when one of us doesn't exist and the other's a legally dead murderer. And besides, I don't need some piece of paper to tell me to spend the rest of my life with Cas."
Sam looked disappointed but he thankfully let it go.
Later that night, once Sam had gone to sleep in his own room (having refused to share a room with Dean and Cas since they got together), Dean sleepily allowed Cas to hold him close while he buried his face in Cas' shirt. He found that he loved to breathe in Cas' scent while falling asleep – Cas smelled like honey and home and thunderstorms and Dean always felt safe when his angel held him like this.
"Dean?" Cas said in a voice that was not quite a whisper.
"Yeah?"
"I am glad that we didn't have a lavish wedding. And you are right, Dean. A piece of paper cannot tell us whether we are bound for the rest of the lives or not."
"Good that you feel that way. Now can I go to sleep?"
"I may not have visited Earth numerous times like many of my brothers and sisters but I do remember a marriage ceremony from many hundreds of years ago. Many people could not afford to hold weddings."
"Can you get to the point, Cas?"
"These ceremonies were very simple. All the couple would have to do was say 'I marry you' to their partner, along with their mate's name. That was all it took for them to be bound in matrimony."
Dean remained silent for a minute. Was Cas hinting at something? And could he just turn around and marry his angel just like that?
'Okay,' Dean thought. 'Let's nerd out like Sammy.'
Dean did love Cas. He knew that. He'd loved Cas for years and, if Cas was to be believed, the angel had loved him ever since pulling him out of Hell. And he'd been so patient with Dean's pigheadedness for years! So time would not be an issue – Cas had proved that he was willing to wait for Dean for as long as it took for Dean to commit. He knew that Cas loved him with a fiery passion, even if Dean felt unworthy of such love and wondered just what he'd done to deserve it. There were thousands of other, more deserving people out there! What made Dean so special?
"I chose you, Dean," Cas said firmly. Dean grimaced. Crap. He'd forgotten that Cas could read minds. "You are the most deserving person of my love that I know. I would do anything for you, Dean. I would pull you from perdition again. I would even go to Hell for you."
"Let's not go that far," Dean joked. "We all know what happens when we sell our souls for each other. Not to mention you really don't want to go downstairs."
"I don't care," Cas said. "I would endure a thousand Hells for you, Dean. I love you."
Dean's breath hitched at those simple three words. What had he ever done to deserve such a loyal, loving angel?
"You were yourself." Cas pushed Dean into his shoulder further. "You are the one I fell for, Dean. No one else."
Dean froze. He slowly opened his mouth and whispered the four magic words that he knew would change his life.
"I marry you, Castiel."
Dean felt Cas tense in surprise. For a single horrible moment, he worried that he had messed everything up like he always did. He never did anything right! But then Cas pressed a kiss to the top of Dean's head.
"I marry you, Dean Winchester."
Dean felt a smile stretch across his face and he removed his face from Cas' shirt to give his angel a long, deep kiss before snuggling back into his shoulder. He felt Cas rest his chin on Dean's head like Dean had done to him a week ago and Dean allowed himself to drift off to sleep while Cas held him close in his safe, protective arms and watched over him that night like he always did.
Dean and Cas never mentioned their wedding night to another living soul, least of all Sam. But they never, ever forgot about it and Dean always felt warm and safe whenever he remembered exactly who he had married, though he sometimes wondered if Cas had actually been truthful about this custom.
Even if he hadn't, Dean decided, it didn't matter. To them, they were married and that was all that mattered.