At the risk of sounding old fashioned I learned that sex is a good way of confusing things in the beginning of a relationship. When I was younger I thought sex should be part of the deal but it always left me feeling progressively lonelier and unloveable when they ultimately moved on (usually after 3 months).
For personal reasons I decided to wait until marriage and be up front with the potential men on the first date. A lot of guys got angry and never called me again. I shrugged them off much easier without all the emotional baggage that sex inevitably throws into the mix.
When I told the ISTP the same thing he visibly relaxed. Not what I was expecting. But now that the pressure was off him we were able to take it one day at a time without a lot of drama and as things progressed I think he really enjoyed testing my resolve.
You can blast my opinion if you want, but I think that most guys deep down inside like to know that a girl who is strong enough to hold them at bay for 6 months or whatever is one they can trust not to hook up with a neighbor after they are married. I think guys actually like the security although many may not admit it in public.
So I would caution all "ye fair and tender ladies, (to) take warning how you court your men . . ." Leave sex for after you know you genuinely like and respect the guy as a person without all the endorphins making it confusing.