Which brings me to the nuances of policing potty talk. Technically, bottom is not a bad word. In fact, considering the range of possible terms describing that physical region, bottom is maybe worse than "buttocks" and more polite than "rear end," but it is clearly on the cleaner end of the spectrum than "ass."
So I have to consider several factors, such as location, intent, and audience. When he tells Amelia that the squirrel in the yard is a poo-poo head, and she laughs, I let it slide. When he tells me dinner tastes like bottom, I object.
Henry has noted that there are exceptions, and he has become sort of a potty talk negotiator. The other night at dinner, when I invoked the no-poop-talk-while-eating rule after he referred to Amelia as a poopy diaper, he immediately apologized. Thirty seconds later he sighed and flipped his wrist and said, "Oh, poo."
"Henry," I warned.
"I'm not saying 'poo' like what comes out of your bottom," he argued. "I'm just saying, 'Oh, poo.'" He flipped his wrist again in demonstration.
And then I laughed, thereby ensuring that potty talk at the table will continue indefinitely.