Don't touch the turtle
A few months ago, Mackay walked by her dad in an unpleasantly stinky state, and Bill asked her, in the phraseology of her grandfather Rule, "Do you have a turd in your pants?" To which Mackay responded, "A turtle?" Since then, it has become an inside joke in our house when we need to change Mackay's 'turtle-ish' diapers.
Today, Bill informed me that things have evolved, and the new lesson during diaper changes is 'Don't touch the turtle.'
Ick.