Me: Only the joey is a cupcake. The rest is a muffin.
timprov: Do the cupcakes breed true when the joey grows up?
Me: Look, I can make you a Punnett Square when you wake up--
timprov: I don't want to be a Punnett Square when I wake up! I want to be a Punnett Square now!
I do wish to clarify that while frosting is a guideline for the important existential difference between muffins and cupcakes, it is not the endpoint of the discussion, which is I think how we got to kangaroos. Either that or we got to kangaroos because timprov should have gone to bed half an hour ago. I'm not really sure.
I am just relieved that there was nothing whatsoever about frosting ducks, geese, or grey ducks. Because that would have been just silly.