Who's on first...?

The boys have this Guess Who? game with a bunch of different characters on it and they like to try to read their names. So we're in the car and Parker asked me what J-O-N spells. I said, sound it out. So he did, "Jon?"
Me: Yep, Jon, just like Grampa, except Grampa has an 'h' in his name.
Jake: Grampa John?
Me: Yep. And what's Nana's name?
Silence
Me: It's Donna
Parker: Nana Donna?
Me: Yep and what about Grammy and Grampy's names?
Jake: Weiss!!
Me: Well, yes, Weiss is their last name, good, but what about their first names? Grampy....? Starts with a 'p'...
Jake: Michael!
Me: Um, no. That's daddy's middle name. Grampyyyyyy.....Pete
Jake: Pete!
Me: what about Grammy?
Silence
Me: It's Karen
Parker: Carrot???
I crack up
Me: No, not carrot. KAREN!
Parker: Oh Grammy Karen.
Both: Hahahaha carrot!!!!