Baby drives back up to Mary's house. We see "THE CAMPBELLS" on the mailbox. Baby and John drop Mary off, but although he gets a sweet but fairly chaste kiss goodnight, he neither walks her to the door nor waits for her to get inside before driving away. Maybe that's why her father doesn't like you, John? Ah, I can't blame that cute kid. Let's yell at Kripke and crew instead, shall we? Look guys, there's no way that in 19 frickin' 73, a clean cut Corporal John Winchester who is just home from the 'Nam does not walk his intended fiancée to the door of the house in which dwells her father who is none too impressed with him. Yeah, I know you wanted a convenient way for Dean to meet up with Mary again, but you should have taken care to make it a good way. Maybe we don't see them drive up. Maybe we close in on them saying their goodnights on the porch, Mary faking like she's in for the night, but coming right back out as John drives off because she knows Dean's lurking. Something. Anything. Am I nitpicking? Sure, but your actors and characters are better than this, so you should be, too.
So...um...yeah. Dean's lurking and talks his way into Mary's house, because he *has* to meet his grandfather, even though Mary tries to warn him off. Inside, Dean aces Grandpa Mitch Pileggi's vampire slayage quiz (decapitation -- not wooden stakes nor silver -- is the way in the Supernatural 'verse) and is all proud of himself, but Grandpa could care less and wants to give him the heave ho because he doesn't trust other hunters in his home or around his family. Probably not the worst ground rule. Grandma Winchester (the mom from Reaper) says, "Knock it off, Samuel," and makes it clear that Mary and Dean get their good looks from her side of the family. She introduces herself as Deanna, invites him to supper, puts Grandpa in his place another time or two, and sets us up to enjoy Dean's realization that Sam is named after their grandfather while he's named after their grandmother. I wonder how long Dashing El Deano will keep that secret from the brother whose masculinity he's constantly maligning.