This really is lighthearted! And I'm going to use the annoying Person A/Person B despite it be absolutely clear which one I am (and that I'm obviously in the right).
Happily married couple get an Indian Takeaway for a rare treat.
Person A orders Chicken Bhuna*
Person B orders Lamb Dhansak*
Then they order a rice, a naan and a side to share.
Person A eats all the Chicken Bhuna, half the rice, half a naan and half the side.
Person B eats half the Lamb Dhansak, skips rice, half of the naan and spoonful of side dish.
Remaining is half the Lamb Dhansak, half the rice and nearly half of a side dish.
Who gets the leftovers?
Person A thinks they should be split and shared (perhaps with the addition of a bhaji or a samosa from the freezer). "All that I have, I share with you" etc
Person B thinks they are their leftovers, and they make a perfect size meal for one and Person A should keep their mitts off as they ate all their own yesterday.
Who is in the right?
YABU - Person A is right - split the leftovers. Caring is sharing.
YANBU - Person B is right and they are entitled to all of their leftovers.
(* I have changed the names of the dishes so as not to out myself 😂)