Aside from the obvious fact that people who act creepy like this are always behaving wrong/bad, I do hope you see some of the irony in your post.

So when is it ok for men to flirt with you, if they are 5 years older, 10, 15? Can they also only flirt with you when you find them handsome?
What about the women who do like older men, is it ok for men to flirt with them? How would those men know in the first place if they have a woman in front of them who doesnt care about the age gap or actually has a preference for it?

Do you take the initiative yourself if you see a potential interesting partner, or do you rather wait for him to initiate the contact? If you like that person it would be ok, but if you don't would it then be creepy?