Dean first tries signing to Cas halfway through October. After six weeks of ASL, he's learned plenty, but has always been too shy to share it with Cas. Too worried that he'll mess up or make a fool of himself. But this is getting ridiculous. Six weeks of whiteboard messages and it's about time he lets Castiel know he's learning ASL.

So there they are, studying together in their dorm room as usual. It's a Sunday afternoon and Cas is sprawled across his bed, working lazily through some paperback novel. Dean is trying to study, he really is, but he keeps looking over at Cas instead.

He's worked out what he's gonna say. He's practiced. Sign language really isn't that hard. He can do this. He can talk to Cas, really talk to him, in Cas's language.

He closes his book. He stands up, crosses to the foot of Cas's bed.

"Um," he says. Cas must sense the tension in Dean's posture, because he looks up. He cocks his head to the side.

Dean skids his palms on his jeans. He signs, clumsily, Do you want to eat lunch with me?

Cas shoots up, book falling to the side. His eyes go wide as moons. He reaches for the whiteboard on the desk, but Dean scrambles forward and catches his wrist.

"I'm, uh, learning sign language," Dean says, his hands following the words. Cas watches the signs, and then his face breaks into a wide smile.

He signs something, but it's too quick, and Dean's already flustered. He makes a face, then makes the sign for don't understand.

Cas huffs a laugh and signs again, more slowly. Where are you learning?

Dean's brain is scattered and he can't quite summon a response in ASL. He surrenders and says, "In class. I'm taking Intro to ASL this semester."

Cas stares at him for a long, long moment. Dean can never look away from Cas's stares. Then, with a soft smile, he signs, thank you.

Dean feels his cheeks coloring. He looks at the wall behind Cas's head and says, "Yeah, whatever." And then he signs again, Lunch?

Cas nods, closes his book, and goes to put on his shoes.

They talk on the way to lunch, in sign language. It's the first time they're able to have a mobile conversation, without pen and paper between them. Cas is grinning unabashedly. His signs are sloppier than Dean's, more casual, but the ease is something Dean will get with practice.

Lunch is awesome. Made awesomer by the fact that ASL is the only language that allows Dean to talk with his mouth full. And Cas keeps signing thank you, over and over and over again. That makes it pretty worthwhile.

So Dean does get better. He starts talking almost exclusively in ASL with Cas, resorting to the whiteboard only for complex conversations. Cas teaches him new vocabulary every day. It's true; immersion really is the best way to learn a new language. Sign language is different than anything else Dean has ever learned, but it's a good kind of different.

Castiel grows to be his best friend. They have busy schedules and separate circles of friends, but they always find time to see each other. They eat breakfast together or they study together or Dean follows Cas to his ASL club meetings. It's for deaf kids and their family members, basically anyone who can sign, and Dean figures it's mostly so Cas has the opportunity to speak in his native language. It's astonishing, the speed and fluidity with which he can sign. Dean likes to watch Cas in that environment – it lights up something warm in his chest.

Dean falls into university effortlessly. By the end of freshman year he's happy and comfortable, excelling in his engineering classes. He's going home to South Dakota for the summer, to Bobby and Sam, and he's far more excited about that than he should be.

One afternoon in June, during finals, he's telling Cas all about it, about Sioux Falls and how tall Sam's gonna be. It was Bobby's decision that Dean had to go to college at all – he himself would've been content working in the garage and caring for Sam – but one of the conditions was that Dean come home for the summers. He hasn't been home all year, and damn, but he misses his little brother.

He wants to meet you, Dean signs. He's slouched in his desk chair, casually facing Cas. You should come up in August, if you can. For a week or two.

Cas nods, and his hands flutter absently.

"Cas," Dean says, and he waves to get Cas's attention back. You're nervous. What's wrong?

Cas looks at him while he signs, then looks quickly away again. It's nothing. I was thinking.

Dean raises his eyebrows, gestures for Cas to continue.

Next year. Do you want to room together again? I know you made close friends from the engineering school, but because I don't know many people who can sign, it would be far easier for me to- he cuts himself off, waving his hands like he's waving away smoke.

Dean leans forward. He signs, what?

I don't want to start over with someone new next year, Cas signs, looking miserable. I like talking with you.

Dean huffs a laugh. Of course I want to stay roommates. You're my best friend.

Cas tenses at that, then signs, thank you.

I thought it was obvious. I learned ASL because I figured I'd be stuck with you. With that settled, Dean leans back in his chair. He starts to open his book again.

Cas keeps signing without forewarning. You made this year good, Dean. I don't know if I could have been happy here without your help.

Dean looks at him for a long, long moment. He's been getting these urges lately, urges to grab Cas by the collar and kiss him. He's getting one of those right now.

But Cas reaches for a book then, his cheeks a little pink, and Dean lets his mind move away. Right now he's content; summer's almost here, and it's been a good, long year. He can cross that bridge another time.

Summer comes. Dean goes home to Sam and Bobby. Sam is a foot taller and still skinny as a stickbug, but nothing else has really changed. Nothing changes in South Dakota.

They didn't talk much while Dean was at school, so he has a lot to catch up on. He takes Sam out to the movies, talks school and girls and sports. Sam's fifteen now, just starting to think about colleges himself. He's smarter than nearly anyone Dean knows. Nearly anyone, because Cas is pretty damn smart.

Dean wondered once, about the English literature thing. How someone who doesn't speak English can study it. But Cas is fluent in English, damn good with words – just in writing. He once explained to Dean that as a child, with few people he could talk to, he read voraciously. His vocabulary is probably broader than Dean's. It's weird, because the way he talks in ASL is so differently than the way he writes in English, but they both have a distinct Cas voice to them. Dean likes that. It's like Cas speaks English with an accent.

They text a lot, through June and July. It's easier than Skype, where signing is unwieldy and cumbersome, and it's obviously easier than phone conversations. Dean tells Sam all about Cas, except he keeps forgetting to mention the deaf part.

Which makes it weird when Cas shows up on Bobby's doorstep in August. Dean's excited, of course; they've been planning it for weeks now, and he's missed the guy. But Sam and Bobby are overwhelmingly confused when they launch into a flurry of sign language.

How are you? How was your flight? Not too scary, right? Dean asks, as soon as he's past the greeting hug.

Cas's grin is infectious, wide and genuine. His hands are a blur. It was fine, of course. It's good to see you again.

Dean just laughs and ruffles Cas's hair. Without spoken words between them, their dialogue has become strangely physical – odd touches here and there, brushing shoulders to say hello.

"Dean," Bobby says from behind them, "you want to tell us what the hell is going on?"

Cas looks past Dean to Bobby and Sam, then signs, will you introduce us?

Dean nods and steps aside to welcome Cas into the house. He has one suitcase, which he drops unceremoniously in the doorway.

"Guys, this is Cas," Dean says, gesturing.

"You didn't mention he was-" Sam says, before closing his mouth with an embarrassed noise.

"Deaf, Sammy, it's not a dirty word," Dean says, but he can feel his smile faltering.

Cas brushes his hand against Dean's. He signs, you didn't tell them?

Dean shrugs and hopes that's enough. "Uh, yeah. Cas is deaf. Was that important?"

"No," Bobby says, "although maybe the fact that you picked up sign language was?"

"Oh. Right. Yeah, I took a class. So I could talk to him. I'm sure I mentioned that. Didn't I?"

But Sam is already recovering from the shock. "Hi, I'm Sam," he says, extending a hand to Castiel. Then, to Dean, "Can he read lips?"

Cas rolls his eyes and nods as he reaches out.

Sam looks embarrassed yet again, but this time he directs his question at Cas. "But you can't talk?"

Cas makes that little concentrated frown of his, then turns to Dean. He signs, Can you explain?

Dean says, "Yeah, he can talk. Or so he says. I've never actually heard his voice. I think he's embarrassed. He was born deaf, so he doesn't know what it sounds like, and he doesn't know perfectly how to use it. But he's not technically mute."

Bobby looks a little uncomfortable, but he pushes his wheelchair forward to shake Cas's hand too. And then – here's the surprise – he fingerspells his name.

Cas and Dean recoil in unison. "You can sign?" says Dean.

"You pick up a thing here and there," Bobby grunts. "I'm no good at it anymore, but I can try for your boyfriend's sake."

"He's not my-"

"I know, I know, quit your yammering." And then Bobby signs, a little inelegantly, Welcome. Dean says a lot about you. Castiel inclines his head gratefully.

Let me get your bag, and I can show you around, Dean signs. He picks up Cas's heavy bag – heavy with books, probably – and lugs it up to the second floor. Castiel follows him, steps light on the stairs. It took a while for Dean to get used to Cas's quiet. But it's a nice, amiable kind of quiet.

Dean shows him the house, shows him the yard, shows him the garage.

This is my car, Dean signs, when they reach the Impala. He considers doing the sign for baby, but decides it won't have the connotations in ASL that it does in English. Next year she'll be at school with me. Man, he's missed the car. It was his dad's, one of the few things Dean has left of him.

They stand together, facing the car. Dean stuffs his hands in his pockets, which limits their conversation. Dean thinks about trying to explain what the Impala means to him. He doesn't talk about his family much, doesn't have the vocabulary for it. And Cas is pretty quiet about his own; it's never been important between them.

It was my dad's, Dean finally signs. He… Dean struggles to find the phrasing for the next bit, lets his hand hang in the air. He wasn't a good guy.

Castiel looks at him with an open, curious expression.

But the car was something he loved. And I know- Dean curses, lets his hands fall. He tries again. I know he loved me too. But sometimes it's easier to love the car than to love him. Or forgive him.

Dean tries really hard not to look at Cas, for a bit. He knows Cas is looking at him.

And slowly, Cas reaches out to take his empty hand. He laces their fingers together.

For someone who speaks with their hands, Dean thinks that means a lot. He thinks it might kind of be like kissing.

He lets his hand be held. He rubs at his eyes with the sleeve of his coat.

Dean loves Bobby – loves him for the care he shows them, gruff though it may be. Bobby is a better father, and a better man, than John ever was. It's only been three years since John drank himself into a stupor and crashed the damn car, two since Dean took that car apart and rebuilt her from the engine up. Dean's still figuring out where to go from here. But having someone like Cas – warm, kind Cas – by his side, it eases the ache.

Dean knows he likes Cas as more than a friend. He doesn't know what his dad would have said about that, but he doesn't know that he cares anymore.

They all eat dinner together, and Dean translates for Sam and Bobby the dumb jokes Cas makes. Sam gets pretty good at speaking clearly, so Cas can read his lips. It's not as hard as it could be. Sam and Cas talk books, and Dean gets a little tired of translating, so after dinner he sends them off with a whiteboard and helps Bobby with the dishes.

"You've got something special there, boy," Bobby says.

"Yeah," Dean says. "Yeah, he's really something."

Bobby looks at him with that skeptical, scruffy look of his. "You learned sign language for him, Dean. I've seen you show that kind of devotion to two other things: Sam and that car of yours. You know what that means, right?"

Dean looks at the plate in his hands, sees his dull reflection looking back out at him. "Yeah, Bobby, I know."

Cas walks in to the kitchen, signing, can I help? Speak of the devil and all that.

He looks really good here. Blue jeans, blue eyes. In the center of Dean's home.

Dean tries not to dwell on that. He tries.

He's gonna do something about this. About them. Just not today.

Today, he's gonna wash the dishes with Cas, and they're gonna make dumb jokes in sign language, and they're gonna watch an old movie with the subtitles on. Because that's easy; that's what he knows. But his feelings are uncharted territory. So he's gonna ignore them, at least for today, at least until he finds a way to say them.

(Sign them.)