My formula is very simple.

If I do the asking, I do the paying.

If I get invited by someone else, I go into it prepared to pay for exactly my own share, hypothetically; but if they insist on paying, I let them.

This applies whether the meal date is platonic or otherwise.

My expanded overview is here:

https://medium.com/checkmate11/the-dutch-oven-of-dating-11c02a3882f