Dean will be so stuffy about the fact that Sam’s a full-fledged hunter but he’s never even gotten the chance!
The amount of sass Sam will get if there’s a hunt where Dean happens to be the more useful size than Sam. So much. Sam’s going to get called all the nicknames. Every nickname. Damn Sasquatch. Why’d he have to go and get so tall?!?! At least Dean’s the only one that can navigate so easily in the vents between them. Sam would practically have to worm his ways into the vents, and that’s if they’re even big enough to fit him at all.