Let’s make it clear, I pay to my parent monthly allowance, I don’t want mention gender *you know why I don’t want unwanted attention*, I have absolutely doing it unconditionally, just paying it out of my spare cash because I want them to have a meal everyday to survive, I’m doing it just like any grown up kids trying to protect their ageing parent, I rephrase, no commitment in doing it, not even a legally bind responsibility obligation, just out of unconditionally want my parent to spend on some food with that money and forget the hardship, but I find it’s a mistake to be feeding them with cash and expect they will appreciate no matter how much I give them, but no they demand more not less, I’m going to say I didn’t expect that, and I can’t find a way to reject them or blame them, this is kinda big dilemma that has no right or wrong way to do it. I think it’s very clear, if anyone else on my shoe they surely know it, btw I’m just making an instance.
For me, if the demand more, then talk to them. Tell them that's only what you can give to them.
Or if you can give more and you are really willing, then why not. They are your parents, they are the one who raise you, it is your responsibility to be the one helping them. If you don't have a family yet then at least let your parents enjoy how you treat them with your salary. It is just a money, you can always earn it, but the memories with them is something that you cannot return once they are gone.