Personally, I think the expectation that the male should pay is sort of derogatory. Men shouldn't be expected to pay for everything as it's somewhat a burden! I think whoever wants to pay should pay, or if both are indecisive you should just split the bill, however sadly most people here think that the man should pay.

I find it somewhat sexist and unfair (why should they be expected to pay all the time?) however unfortunately I cannot change the majority's opinion.

It is considered a courtesy when going to dinner or something like that, but if you are going shopping or something like that, and the guy always pays, it can seem like you are gullible, or easily taken advantage of, or possibly just plain stupid.

Long story short: Pay for her, but not 100% of the time.

Well having boyfriends or girlfriend mostly are in privacy in my country they don't have it in puplic especially in conservative area in my country while the liberal areas are okay

In my country consider the man if he loves his wife or fiencè must be Generous and chivalrous so he should pay everything for her or else consider him stingy

I don't think it's a bad habit since he is able financially to do

In my country it is a matter of tradition that the man is the one to pay in the restaurant. But nowadays it doesn't necessarily mean that he covers the total expense. It's rather than he is responsible for the payment process. 
Of course when the man invites a woman - it is obvious that he should pay (though the woman may insist on paying for herself). When these people meet frequently they usually share the expense or at least they allow to pay for themselves every second meeting - 'Whose turn is it today?'.
I have seen that young people who have no their own money yet (like students getting their money from their parents) share the bills or the boy pays and the girl refunds her part later. Or they decide to give a part of their money every month to 'common wallet' to have funds for the things they do together. I think it's the best training, when they plan to be a family in the future. 
All the money the married couple possess usually belongs to both of them (with some exceptions according to the law), even when they have separate bank accounts. So whoever pays the bill technically  - they do it together. When we go with my wife to a restaurant or even shopping, she usually asks 'Have you enough money or your credit card with you, honey? Ok. So I may leave my wallet home to not lose it.'
On the other hand it was very popular in 20th century, in the community where I live (mostly coal miners), that the man was the one who provided most of money for the family and was giving most of it to his wife, who was responsible for the house including its finances. He only kept a small part of money to himself to be able to have a beer with his friends occasionally.