I've got ya allllll beat
Harry Potter and the Philosopher's Stone
Dudley: They stuff people's heads down the toilet the first day at Stonewall. Want to come upstairs and practice?
Harry: No, thanks. The poor toilet's never had anything as horrible as your head down it -- it might be sick.
Or
Harry Potter and the Philosopher's Stone
1st Weasley Twin: Oh, are you a prefect, Percy? You should have said something, we had no idea.
2nd Weasley Twin: Hang on, I think I remember him saying something about it. Once --
1st Weasley Twin: Or twice --
2nd Weasley Twin: A minute --
1st Weasley Twin: All summer --
Percy: Oh, shut up!
Or
Harry Potter and the Philosopher's Stone
Harry: So light a fire!
Hermione: Yes... of course... but there's no wood!
Ron: HAVE YOU GONE MAD! ARE YOU A WITCH OR NOT!