snork!! Someone's obviously seen the old 50's Superman TV show. You have to feel sorry for Snape, he's suffering the death of a thousand ridicules and they're all in public. If Brother Z is indeed Harry as seems likely, you have to wonder how he slipped off to study for so long. Obviously not a time-turner in its normal usage, but something along those lines. he's cleary been studying intensively and learned a lot, both about magic and about himself. I'll be interested in seeing when he's revealed to Luna and Hermione; IMHO, Luna will tumble first when she notices a familiar aspect in something Brother Z does.
Yes, I grew up on superman (although not in it's first run -- I'm old, but not THAT old). And Snape's humiliation has not yet begun. Luna will suspect, but not know.