The current funniest thing about my work in progress is that I have no idea how 12 year old girls curse. And my main character, as well as her former best-friend/current nemesis, are both twelve year old girls who are provided with many opportunities to curse (even though we're only about 4 chapters into the story).
So, instead of swearing outright - which, probably? is what 12 year-olds do? - I mean I realize my 13-year-old nephew probably has a truck driver's mouth around his friends, but here I must give my standard "I don't really like cursing, and was a total goodie two shoes as a child, and probably didn't curse in my head, let alone out loud until I was graduating from high school" explanation*.
Either way, for right now, in the NaNoWriMo flurry of words, I'm inserting different ridiculous made up curses, like "Shnikies" and "Zoinks."
So, basically, my two main characters sound like they are directly out of a Scooby Doo cartoon. Eventually, when the time for editing comes, this will become a problem. Right now? It's making the re-reads pretty freaking hilarious.
*If you have any opinions on what curses are popular with the tween-set, please, feel free to share them in the comments.