Last Names

Me: "Emil, what's Fred's last name?" Emil: "Young!" (not too surprising as Fred told him the previous day in the car, but I'm impressed with his memory) Me: "What's your last name?" Emil: "Kristen." (not bad) Me: "What's my last name?" Emil: "Aw-aw!" (ha!) Me: "What's Oskar's last name?" Emil: "Chubby!" (hahaha!)