His fingers clutch the steering wheel, unable to catch his breath after his brief but explosive run in with Lucifer, who Dean just found out is living inside of his best friend. He can't escape the sound of his voice, Cas' voice, as Lucifer sneered at him, telling him his plans, his reasoning as to why he's needed against the Darkness, but the worse part, the one that stings is, Cas did indeed say yes.
He said yes. Cas said yes.
And it was Cas' own voice telling him why. Why he would even do something so goddamned stupid as letting the devil wear him. "He felt useless. That no one would miss him. There wasn't anyone telling him otherwise."
That's when Dean almost lost it. He knew he'd been a shitty friend, he was aware that the years he spent with the mark had turned him cold, giving off the vibe that he was uncaring. But he did care. He never stopped caring. He never stopped…
But it's too late, isn't it? Cas is gone, living behind another angel, another fallen angel who instead of loving humanity as Cas does, loathes it. Opposites living in the same vessel yet sharing such a similar tale.
But it won't end here, oh no. If Dean is sure of one thing, it's that he won't stop until he gets him back.
Once he reaches the bunker and heads inside, throwing his keys on the table, and ignoring Sam's meaningful glares, he takes a deep breath and lets the awful news try to make its way past his lips. Sam needs to know.
"I ran into him. Lucifer. He's in Cas, Sam. He said yes."
Dean can't even look his brother in the eye. It's stupid really, because Dean shouldn't feel like it's his fault, but he does. He could have told Cas a million and one reasons why he's important to him, why he matters, what a damn hero he is in Dean's eyes. But no, he said nothing to him and let his friend's self doubt spiral so far out of control that it drove him to do something unimaginable.
"What? What did Lucifer say?"
Dean's rage starts to build, hearing it over and over again in his head. The anger in him is making his blood boil now, and yes, he's fucking angry but not at Cas, not even at Lucifer. He's mad at himself for being such a blind idiot.
"Nothing, that's it," Dean barks, still avoiding eye contact. "I'm gonna take a shower."
He walks down the hall, feeling Sam's glare burning through the back of his head, but he just can't talk about it right now. He needs a hot shower, followed by a bottle of whiskey, and then maybe he'll have the guts to start praying to him. To Cas. If he can't tell him to his face, he'll tell him everything in prayer. It's time. He has to do it.
He thinks about what he is going to say to him. He could just write down a list of all the reasons Castiel means the world to him. Or he could just tell him the damn truth about his feelings, because really, he had meant to but the words had always refused to escape his mouth.
He had imagined it hundreds of times, him telling Cas something simple like, "My life is brighter with you in it," and he'd always laugh at how ridiculously corny it sounded but at the same time, he'd imagined Cas' reaction to it, and how his mouth would curl into a small smile, that smile that had always given Dean the warm fuzzies for reasons he has yet to even dissect.
What he'd give to see that smile and those blue eyes looking back at him like he's the single most important person in the world. Those eyes that could change from fierce to loving in a split second.
As the warm water hits him, he closes his eyes and tries to imagine all the times he'd seen Cas happy. It's been so long, so fucking long and it hits Dean hard in the chest. His tear filled eyes open and he rests his forehead against the tile as he let's it all out, crying until there's nothing left.