When all else fails, confuse them
“Timmy, please walk in the house.”
“Yeah, Timmy. We don’t run in the house.” This is Nigel, visiting for the day. (And don’t you just HATE that “yeah” thing they start to do around the age of 3 or 4? Isn’t it just too totally obnoxious for WORDS?)
“Nigel, you are riding a bike in the house. I don’t think you can talk.” (Which is not entirely fair. The bike is a Skuut, and they’re allowed to ride it in the house, whereas they are not allowed to run. Why yes to the bike and no to the running? Remember that “pitter-patter of little feet” thing? Running is MUCH, MUCH louder. So, not entirely fair, my comment, but still. The irony of his position is unavoidable, to everyone but him.)
Of course, Mr. Literal three-and-a-half year old takes this … literally:
“Yes, I can talk. See?” He opens his mouth wide, the better to show me his talking apparatus.
“No, I mean, because you are riding a bike in the house, you are not in a position of moral superiority.”
. . . . . . . . . . . “Oh.”