Dean and Castiel in “Unfinished Business”

Dean

So what? God's my copilot, is that it? [Castiel just looks at him, and Dean glances over again.] Well, you're a regular Chatty Kathy. Tell me something, Sam would have wanted in on this. Why not bring him back?

Castiel

You had to do this alone, Dean.

Dean

And you don't care that he's tearing up the future looking for me right now?

Castiel

Sam's not looking for you.

Dean

Alright, if I do this, then the family curse breaks right? Mom and Dad live happily ever after, and- and, Sam and I grow up playing Little League and chasing tail?

Castiel

You realize, if you do alter the future, your father, you, Sam, you'll never become hunters. And all those people you saved, they'll die.

Dean

I realize.

Castiel

And you don't care?

Dean

Oh, I care. I care a lot. But these are my parents. I'm not gonna let them die, again. I can't, no, not if I can stop it.