I was invited out for the dat, the deal was I sorted out dinner and they sorted tea.
I made a big (6 people) picnic with plenty of food for everyone that they liked.
They bought fish and chips for everyone.
I can't eat fried food, they know this and I don't eat meat or fish.
The choice was eat it or go without.
Aibu to think that's not fair because the other person thinks they kept their side of the deal by providing food.