"J-O-H-N! How many times have I asked you 'not' to leave the bloody toilet seat up?" Alison shrieked, from the bathroom.
"I dunno, sweetheart. I kinda lost count after two hundred, or was it three hundred?"
"Enough with the smart mouth, I'm serious."
"And how many times have I told you? I 'do not' leave the toilet seat up, okay?"
"You what! There's only you and me in this house."
"Once again, I 'never' leave the toilet seat up, and I can categorically prove it."
"Oh yeah, and how can you do that?"
"Because I always pee in the sink."