Everyone has a friend who says they don't want any pizza when everyone is pitching in for an order, but is "famished all of a sudden and will only eat a slice" as soon as the boxes full of delicious, cheesy magic arrive.
Cats are always that friend. You give them a home, buy them food you can't even eat and then they get their paws all over your dinner.
The worst part is cats are amazing, and they are extra cute trying to be stealthy stealing pizza. It's a horrible tradition and it should never stop. Check out the above clip and just be happy it isn't your pizza being gobbled up by a freeloader.