Joan's 3 month rule?

This is kinda hard. I think it depends on the person you're with on when you should be intimate with another and your own values. I can see where Joan's 3 month rule came from because often women sleep with men early on in the relationship only for the man to leave them etc. If you hadn't slept with him yet, then you won't feel as bad. However, some guys will still leave you if you don't give it up.