Harry came out with some good ones. At one point I was being uncharacteristically playful, being an announcer at a race:
Me: And in lane 1, we have a new competitor, Mr Harry Williams!
Later, when his turn,
Harry: And here is Mr Mummy Ali Williams!
and then later,
Harry: I've got my two mums!
Me: Do you know who else has two mums? (thinking of baby r, toddler of our friends)
Harry: big grin - Tom Tom!
1, 2, 3 -- aahhhh!