Just do what I do when I'm dating a girl. Every time you go out, one day you pay, the other day they pay. Unless it's a resto and you're taking her out for a special occasion, then you pay.
If the girl told me to pay everytime, I'd end up stealing her purse and CCs to get back at her. Sell her knock off Gucci purse to a stupid teeny for 50$ ... thats whats up. lol