Zero-Sum Econ Applied to Ice Cream

I'd purchased enough ice cream for each of us to have two servings, but baby Payge wasn't going to be taking her fill (she'd already smeared herself with the first serving, so we were telling her "No more."). As we went to put her serving in the freezer, Zac pipes up, "Hey! Dad! If Payge isn't going to have two ice creams, somebody has to have three..."