My mom and stepdad never let us pay when we offer. Not once. My dad frequently will ask us out to dinner or for pizza and ask us to pick it up and not pay. My dad has way more money than my mom.
random thoughts. How is your dynamic? Will you let your kid pay when you're older? I can't see doing that unless they are super well off.
My parents always pay for us. They are always treating us to stuff too and buying our girls stuff. They are very generous. My IL's on the other hand always expect for us to pay even if they invite us out.
My parents pay often, but once in a while they'll let us pitch in our share if we beg. It was hell to get my mom to put the checkbook down so we could pay for all of Mothers Day.
We've only ever taken BF's mom out, she's never paid for us (or for her share.) Which is fine, we just can't do it as often.
About half and half with my mom. ILs are much better off and usually insist on paying for everything when we see them. I think they feel a bit of guilt since they live 10 hours away and don't get to see DS often.
We have been able to split the bill about twice with my parents and take them out maybe once or twice. With the IL they usually pay, but we have split a few really expensive meals.
My in-laws always pay. And for our anniversary/birthday dinners without them, they'll call ahead and pay for our bills. (They started doing this for our 1st wedding anniversary.) We just recently surprised them and did the same for their anniversary dinner.
My mom pays often, but we don't see her too often. And dinners with her are usually things like In-N-Out.