I'm of the opinion that whoever asked for the date should pay, but even if he asked me out I'll still offer to pay half . . . but like GMUBunny said, if he insists on paying, I'll let him pay.
If you're out with a girl and she won't accept your insistence to pay, you could offer to let her pay for the tip, or for dessert. That way you're still being generous but she still feels like she made a contribution.
If she REALLY keeps insisting, let her pay. Why pay more than you have to?
