What do you think would happen....?

The reason clubs have "free ladies nights" is because they want lots of eye candy there to satisfy the male clientele. If you don't look "hot" and "y" by society's standards, they might discriminate against you and make you pay. But the entire concept of "free ladies night" is inherently ist and discriminatory anyway. What I'm saying is, don't expect fairness or morality from a place that will use women to make money.