I like that *look* Dean gives Sam in front of the mirror. Before he says Bloody Mary for the third time, Sam glances at Dean, almost like he's looking for...permission? Reassurance that Dean is right there?

And Dean actually sort of just rolls his eyes as if to say Dude, this was YOUR idea but with an undercurrent of watching me trying not to show how scared I am. Like Dean trusts Sam's idea, but he's deeply worried. (And this is why I adore Jensen Ackles' Dean performance so very much :)