Sam would definitely use the opportunity to prank Dean constantly. Cas would make a nest out of Dean’s clothes. So since Dean’s clothes are all covered in cat hair he’s gotta wear either Cas or Sam’s since he doesn’t want to be constantly itchy.

Mmmm. This is good. I like this a lot. 🙂
So the question is, which of the cats is going to keep knocking Dean’s stuff off everywhere? Which one of them sleeps on his face?
And also, wouldn’t a good solution be for Dean to just walk around nakey? Sam’s pants are too tall and Cas’s are too big in the thigh and waist.