I'm with EasyEJL on this. The best relationships i've had were ones were we slept together in the first 2-3 times we met up. I find that waiting longer than that when you are seeing someone for 3-4 hours at a time on over 5 occasions is just pushing it.
We guys are hard-wired to have sex on our minds virtually every waking hour, so the longer you deny us the more we want the sex rather than the girl, if for no other reason than to feel that we didn't waste all the time dating/flirting/talking to you for nothing. Plus, guys HATE feeling that they are being led on, and today when SO MANY women just want a guy to chase after them because they want the attention but have no intent on even kissing him, the last thing we want to do is spend time, money and energy on a selfish ****-tease.
The 3 best/most passionate relationships I've had involved sex early on and in an awesome passionate manner. The last one was so great due to how randomly it came about. I was flirting with this girl for 3-4 days (texts, msn etc) after having met her through a friend on 2 occasions, and then one time we accidentally bumped into each other in town we ended up doing some shopping together, having lunch, going back to her place for a drink and we barely made it to the bedroom (we literally left a trail of shirts, socks and shoes along the way!!!).
it didn't last very long (3 months) but I wouldn't trade it for a different relationship were I was being put through tests for a 4-5 weeks just to see if I cut it And I'm someone who hasn't had a proper girlfriend in nearly a year. I've currently got a "friend with benefits" who I see once every 2-3 weeks at her place and I'm perfectly content to keep that going until I find someone I find interesting.
Other than I see no reason why people should be in relationships simply for the purpose of being in one (ie they feel lonely, insecure without a bf/gf).