Brony – think about it this way:
Once a girl is married, there are times when she is not allowed to wear perfume for her husband, (the halacha is that he cannot smell his wife’s perfume, therefore the only way this can be kept is if she doesn’t wear it). How much more so for a girl who is not yet married to put it on specially for a date! You wouldn’t start touching up your makeup in front of the guy you were dating, would you?