F.U.N.! (Fuckin' Uber Nice!)
The only thing you can say when you're having so much fun it hurts!
F. U. N.! I just got a dog and I'm already training him to dance!
F. U. N.! I'm wearing my pajamas to school and I don't care!
F. U. N.! I just got a 100 on my test and I'm still screaming!