(Sam falls asleep in the car and Dean messes with him...)

Dean Winchester (singing loudly): A fire of unknown origin took my baby away...

Sam Winchester: Ha-ha. Very funny.

Dean Winchester: Sorry. Not a lot of scenery here in east Texas. Kind of gotta make your own.

Sam Winchester: Man, we're not kids anymore, Dean. We're not gonna start that crap up again.

Dean Winchester: Start what up?

Sam Winchester: That prank stuff. It's stupid and it always escalates.

Dean Winchester: Oh, what's the matter, Sammy? You afraid you're gonna get a little Nair in your shampoo again, huh?

Sam Winchester: All right. Just remember, you started it.

Dean Winchester: Bring it on, baldy.