It is only proper.
Movies, dinners, museums etc. Doesn’t matter if it is your lady friend, or just a friend or your mother. You should pay. If it is a two part activity, and the girls insits on paying for something, make her pay for the cheaper part.
When in a relationship, I always use the 2 to 1 method. I pay for two things, then she can pay for the next thing. However, this is where gentlemanly cunning comes into play. Plan out purchases in advance so that every third purchase is minimal. For example, perhaps you are planning a couch movie night. First buy the dinner, then buy dessert from another place. Then have her pay for the $1 movie rental from Blockbuster Express.
Other Tricks to Prevent her from Paying:
– Instead of asking the waitress for the check, just hand her your credit card
– Use the internet to pay for things in advance
– Use misdirection to send her sneak away to the cash register when she isn’t paying attention
– Sneak money back into her wallet when she isn’t looking