"Stop avoiding the question. What did it cost you?" Dean repeated, his voice firm. If Sam were here he'd say Dean sounded scarily like John in that moment, demanding an answer. But he wanted to know. He didn't like when others sacrificed themselves for him, even in the smallest ways. Cas had hit the nail right on the head all those years ago in the barn. You don't think you deserve to be saved.
As the Angel shook his head, Dean clenched his jaw like a stubborn child. Heck, to the ancient being in the car with him he probably was still considered a child. "You're right. I don't deserve this torture. But me sleeping isn't going to stop the fact that if you are taken back, you die." He ground out, wanting Cas to just stop with the talk of sleep and just listen. "You want to know what plagues my thoughts at night? You. That's right, you come back through that rift and you die, Cas. Lucifer came through behind you and guess what? Light's out. Wings burnt in the ground. Game over, buddy."
He drew in a sharp breath and looked back out the front windscreen of the car, letting out the breath with a huff. "I know you said you wouldn't leave. But you've got no control over that. None of us do." Looking down at the 'hex bag' he still held in his hand, Dean let out another sigh and licked his lips. "What we do have control over is what happens while we are here. And Cas, that means you can't be throwing yourself under the bus for me anymore." I'm not worth it.