Fun fact, this works with very young children as well. Give them one cookie and yourself two cookies and they're dissatisfied. When you then break their cookie into two halves in front of their eyes it's fair again for them.

Can't remember when that stops happening I think at three or four. Surprisingly late.

Our version with our first cat was like:

Was your human late with your breakfast more than 3 days in a row, or 5 days in the same calendar month? Call me, Baby D, Kity Attorney's Office.

Did your human give some of your food to the outside cat? Call me, Baby D, Kity Attorney's Office.

Did your humans prevent you from attacking the outside cat, even though he was right there, outside your window like he owns the damn place? Call me, Baby D, Kity Attorney's Office.