C going up the steps: [collapse on stairs] OOOOOFFF!
M gritting teeth: Wow, you must really be tired - guess that means we can't play Scrabble before bed.
C: It was just an accident, really!
M: It's not an accident the 12th time - get moving.
C: [collapse on stairs] Oooops, I just tripped!
It's not good for my dental work to sound like a harpy, but I swear the next time she's going to school barefoot.