In Metallicar on the way to the Montgomery's, Dean tells Sam he's good with having a chat with their suspected Rugaru. "I just want to know if push comes, you're gonna shove." Sam is now over-identifying with Jack so strongly that he can't keep focused on the fact that Dean's willing to talk -- that he just wants to know what to do if talking doesn't work. He gets on Dean about calling Jack 'this guy', reminds him he has a wife, and blah blah blah. He's so obvious, even Dean sees it, and accuses him of letting his emotions get in the way. When Sam comes over all obtuse, Dean spells it out for him. "You know, nice dude -- but he's got something evil inside of him. Something in his blood. Maybe you can relate?" Meeee-ow.
Sam twitches his nose and I wonder if he's got powers like Samantha Stephens, which makes me want to see the Winchesters take on Endora (she'd kick their asses). "Stop the car." Dean is puzzled so Sam clarifies. "Stop the car or I will." Hmmmm. Dean pulls off the road and both guys get out of the car. FIGHT FIGHT FIGHT FIGHT! Sam says, "You want to know why I've been lying to you, Dean? Because of crap like this." Damn it, they're just going to bicker. Dean wants to know what Sam means. "The way you talk to me. The way you look at me -- like I'm a freak." Well you are 75 feet tall, Sam, and make the possessed vomit out their possessors. Not hardly normal. "Or even worse, like I'm an idiot -- like I don't know the difference between right and wrong." Eh, sometimes that's you; sometimes it's big brother. Dean wonders if Sam does know the difference, because he's been sort of dark-side, lately. Sam tells Dean he has no idea what he's going through, and that does it. Sam, I generally find you ridiculously sympathetic, but every time you talk about what you've been going through, I want to get a ladder, climb it, and whack you upside your ginormous head, because your brother spent the summer in actual Hell. You should have just skipped that part and gone on to what you're going to say right after Dean booms at you to enlighten him. That's your cue. Go ahead. "I've got demon blood in me, Dean. This disease pumping through my veins and I can't ever rip it out or scrub it clean. I'm a whole new level of freak. I'm just trying to take this curse and make something good out of it, because I have to." Dean realizes this isn't the time to tell Sam to stow the touchy-feely self-help yoga crap (bitch), so he changes the subject back to talking to 'this guy' and when Sam harrumphs at him, he says, "I mean Jack, okay?"