First of all, no. No man is entitled to sex. I will probably get banned for saying this, but... It just doesn't make any sense whatsoever. If he has shown you that he is a great man and potential romatic partner, why would you try to use this to prove it?

In my opinion, this just shows insecurity in one's ability to choose partners, immaturity, and lack of self-esteem. If the only way you have to keep a man "interested" is by not having sex with him (something like the 90 days rule), you don't really believe you are worh the effort yourself. I mean, if you are a woman who likes having casual sex/hook ups, what is the big difference here?... It just comes off as immature testing to me.

Note: I'm already expecting a bunch of downvotes and insults to be thrown at me for this, so keep them coming!

EDIT: I'm not saying stuff like "have sex on the first date!" I'm talking about the more extreme stuff like the rule I mentioned above.