In parts of Pennsylvania, "Mom mom" is used to refer to a grandmother and "Pop pop" to refer to a grandfather.
So Lois, as a great grandmother, might be "Mom mom mom," or "Mom cubed." Clark could be "Pop cubed." Or maybe even "Corny," as a pun on the fact that "Pop pop pop" sounds like popcorn popping.
Disclaimer: I don't use "Mom mom" or "Pop pop" myself, and I'm not sure whether they would refer to both sets of grandparents or only to the maternal grandmother and paternal grandfather respectively.
Joy,
Lynn
