I made myself sad. I hate death fics. Well, I hope it will make you cry! :)
One of the cons to being a hunter is that you never know when your last hunt is going to be. It could be after years and years of doing the job and never suffering more than a few bruises or a broken bone, and you're just so tired and don't want to fight anymore. It could be on your third case, when you're not really experienced and you just want kill as many monsters as you can, so you don't take too much precaution. It could be on a good day, when it's supposed to be something simple but this one thing goes wrong and you don't make it out alive.
Dean used to worry about all that, when he was a lot younger, but at one point he stopped. Dying on a simple hunt began to seem a too good option, with the apocalypse hanging over their heads and then the leviathans and angels and demons and the world that needs saving again and again. And yet, every time something major happened, Dean made it out alive, wondering why in the world it was him who had to live and not any of those innocent people that died for him.
He always knew he was going out with a gun in his hand. His dad knew it, Bobby knew it, Sam knew it, everyone knew it. He was a hunter, that's just how it was going to happen.
It's supposed to be a simple demon hunt, just Dean and Cas practicing killing things. It escalates when instead of one demon it's five, and there's also a witch with them, and the fight gets bloody real quick, and Cas doesn't have time to scream to Dean, to warn him, before the demon he's wrestling pulls out a knife and plunges it into Dean's stomach.
Cas isn't supposed to be there right now, with Dean's head in his lap, rocking back and forth and whispering that 'it's gonna be okay, you're not gonna die, you can't die, don't leave me Dean, please don't die' and more. The demons and the witch have vanished as soon as Dean collapsed to the floor, coughing blood and Cas couldn't find it in himself to care where did they go.
Cas can't help but blame himself, because if he had still been an angel, he could have just healed Dean. And if he still was an angel, they wouldn't have had to even be there. They wouldn't need to practice hunting. Dean wouldn't have been stabbed. They'd be laughing and eating burgers and fries in the diner they saw earlier because Cas could have just smitten those demons and witch before anything even happened. But he's human, he's so painfully human and the pain is so much more intense, and there are tears streaming down his face and his fingers are shakily running through Dean's hair, not minding the cold sweat.
"Please, Dean, you can't die. I never… I never even told you that I love you. I never even kissed you. We haven't watched Star Trek together, like you said we would. You- You have to stay alive, be okay. What about Sam? You can't just leave him. You can't just leave us like that Dean, please!"
More tears come down his face when Dean doesn't reply. His green eyes move slightly to lock with Cas' blue ones and he mouths 'I love you' and then 'I'm sorry' and Cas just pulls him closer and clutches him tight, and refuses to look as the light in Dean's eyes go out, and all there is left is a glassy reflection and Dean's slightly parted lips, still with his dying words on them.
Cas rocks them back and forth, and his head is buried in Dean's shoulder and he sobs. He never wants to move, not when Dean is still warm and Cas can almost pretend to hear his heartbeat. But it's not there. It's gone.
He keeps expecting Dean to just look up back at him again, to say 'surprise, I'm alive!' and get a goofy grin on his face. He keeps expecting some kind of miracle to happen, like it always does, but he knows this time it's too late, there's nothing left anymore. There's no longer an angel on their shoulder to make it better, there's no God to fix it.
And Cas knows he's going to have to let go. He's going to have to pull himself away and call Sam and somehow tell him that his big brother is dead. And he's supposed to listen to Sam saying 'ha ha, very funny, now give me Dean' because he doesn't want to believe it, just as much as Cas. And he's supposed to be on the other side of the line when Sam realizes and hear the pain and tears in his voice and start crying as well, because this is a nightmare, this can't be real.
And they're supposed to burn Dean's body, because this one is final. And they're supposed to move on with their lives and save the world again, and hunt monsters, and act like everything's fine with Dean gone, because that's what he would have wanted them to do.
But this is not just any other loss, this is Dean they're talking about. It's Sam's big brother and Cas' best friend and the righteous man who's so selfless and wonderful and Cas is so insanely in love with him.
And he IS all that good. He still is, not was. Because he's not dead, he can't be dead. Not now, when it was getting better. Not now when he was starting to forgive Cas, and Sam was starting to get better after the trials, and Kevin was getting back on his feet again.
He can't let Dean go, he can't just walk away, but he's going to have to. Right now though, right now he can still pretend for a few last moments that Dean's still breathing and that he's going to wake up every minute now and frown at their blood covered clothes and how much laundry he'll have to do, and Cas would say he can do it but Dean wouldn't let him because of the last time Cas did the laundry and everything came out pink.
Cas is just going to pretend that everything's still okay.