[Dean hates that expression on Sam's face; he hates that it's both Sam's face and not, the passenger along for the ride pulling all of the strings, using his brother like a puppet. He itches to throw a punch; he settles for a scowl, only just barely containing the depths of his irritation.]

I think it would be something more than flannel that would get Sam to let some...thing like you in.

[He can't actually hurt the Devil; Dean knows this, and so does old Satan there. Yet that doesn't stop Dean from attempting, using his words if he can't use any actual weapons. He wonders if it's possible for a dream to leave someone tired; he's exhausted and he's still goddamn asleep.

Dean hates the way that sounds, like Sam risked taking on Lucifer to...what, save the world, and not expect to get screwed over in the end? Since when has that ever worked out well for either of them?]

Or, and hear me out on this, you're just being the biggest bag of dicks.