Where's papa's seat?

Mats is obsessed with where things belong. If you put something back in the wrong place, he will let you know. And every time we get into the car, he points to his seat and says "Mats' seat", the driver's seat is "Mamma's seat", next to him is "Oma's seat" and "Tante Lien's seat", and the passenger seat is "Opa's seat". Sorry, Joost. No room for papa.