padfoot: That's what I'd like to know.
Hullo, you look familiar; do I know you?
moony: Could be, chum.
You wouldn't happen to have gone to Hogwarts at some point, would you? Perhaps you were a classmate of mine?
padfoot: Right, that must be it.
You look a bit dodgy to me, though. Weren't a Slytherin by chance, were you?
moony: What, me? A Slytherin? Of course not! I'd take offense, but you seem like a rather amiable sort of fellow.
Gryffindor, through and through - I was even a prefect. And yourself?
padfoot: Oh, I got tossed off the Gryffindor Quidditch team for a) fighting, b) cursing, and c) being ruddy awful at Quidditch.
I am an amiable sort of fellow, my good man. You should see me when I'm at home.
moony: Well, it sounds as though I had a bit more, uhm... illustrious academic life than you did, but to each his own. Your prefect that year must have been particularly lackadaisical to let you get away with all that. It's a wonder that fellow got picked at all if you were continuously getting away with things of that sort!
And if you're offering an invitation, I wouldn't mind stopping by your place for tea and scones sometime. Unless, of course, you'd rather pay me a call.