A/N: Because Destiel is my OTP. Shh, just read.
(Takes place some time after the mid-season finale of season 7. I want to get this thought out before season 7 returns this Friday.)
"I wish I knew," Dean mutters quietly to himself, careful not to wake Sam.
He has his head bowed, his eyes open in the dim light of the streetlamp peeking behind the curtains of the cheap motel room. His hands are unfolded in front of him, dangling from his knees. He's just sitting there, on the edge of his bed, praying. Or maybe it isn't really praying, because Dean still is skeptic to religion and belief in anything other than what he's seen with his own eyes. But he believes in Castiel. Even now, after he's gone. Again. But it might be for good this time.
"I wish I knew," he repeats, trying to keep his voice steady, "Where you were, and if you're really dead or not. I can never tell with you, can I? Just when I think you've gone and blown up or something, God or someone brings you back. But this time… I don't know. And it scares me, Cas. It makes me sick not knowing if you'll come back and help us, or if you're really gone."
He brings a hand up to his face and rubs between his brows, the tension there threatening to sprout tears. But he's cried enough already, time and time again when Bobby and Sam weren't looking. But even Bobby is gone now, too, and all because of those damn Leviathan. Which, by the way, were technically Cas' fault, and yeah, Dean isn't sure if he's fully forgiven Cas for opening up the door to Purgatory and taking in all those souls and trying to become the new God and letting in the Leviathan in the process, but despite all that… he still misses the guy. That angel was… well, Dean doesn't like to think about it much, but he was something special to the older Winchester brother.
"Cas, if you're listening… If you can hear me at all… Please find a way to come back. We need your help. We don't know how to kill these things, Bobby's… gone… and it's just me and Sammy. We might be some of the only hunters left who even know about the damn things or the fact that the apocalypse and the Purgatory thing even happened! We're all that stands against them, the only thing between them and the world, and I could use just one more… one more person to help fight."
And of course this is only half the reason, really. Dean has never been very good at facing his own feelings, and when he has, the outcome has never been very pleasant. But even he can't deny, at least to himself, what he feels for Cas. He called the angel a brother, but that wasn't true. It was the closest thing he could say to "I love you" without sounding… weird. And awkward. And wrong. Because Dean was really hurt, okay? He was literally wounded when he found out that Castiel was working with Crowley, that Castiel was trying to gain a bunch of power in order to defeat Raphael, and that Castiel didn't think or try to reach out to Dean for help, or at least for his opinion.
And yeah, okay, so Dean never wanted to nor thought he could believe it – all the "jokes" Uriel and Balthazar made ("He likes you," "The one in the dirty trench coat who's in love with you,") and all the times Cas hinted at it ("I did all of it for you," "Dean and I do share a more profound bond,") – but it's there, and Dean can't ignore it now that Cas isn't around to possibly see Dean ignoring it.
There's something there between them, something strong and painful and wonderful. And now it's all Dean can do to try and get it back.
"I forgive you, Cas. I should have forgiven you when you asked me to, but I was being stubborn and stupid. I felt betrayed, so I wanted to you to know it, but I didn't think you would die. I didn't know that the Leviathan would tear you apart and mess you up so badly. I didn't know –"
And shit, here come the waterworks. Dean grinds the heels of his hands into his eyes, warding them off, but it's no use. He's crying again, third time this week, because Bobby and Cas and Ellen and Jo and his dad and his mom and everyone left him. Not by choice, of course, but it hurts all the same. They're all gone, and no one's left to help, only Sam, but Sam is in the same boat and they are both so, so tired of being the only ones to bear all the fighting, all the pain, all the loss, and all the responsibility.
So part of it is guilt. Part of it is shame. Part of it is selfishness. And then part of it is love. That's why Dean wants Castiel to somehow be alive, and somehow return to him. He wants Cas back because Cas can help share the burden, can help ease the pain, and can help Dean stay on his feet, because even Sam can't do all that when Sam also needs to be protected, and Sam also needs to fight and has his own pain.
"Do you get it now, Cas? I need you! Okay? There. I said it. I need you. So get your ass back here some way or another or so help me, I'll find a way to bring you back myself!" Dean whisper-shouts under his breath, the tears like acid on his face as he bends over further between his legs, cradling himself and pretending that everything will work out okay, and that they really can save the day, and that he doesn't believe he and Sam are going to die (again) like the rest of the people they loved, and he's going to keep pretending that Sam isn't actually awake and listening in the bed across from him.
Because pretending is something Dean is good at when it comes to not dealing with ugly, sorrowful, confrontational things, and he'll be damned if he isn't going to change that now.