Well, you being a guy in all I think you are the one that should put off sex with her until your 2nd date or 2nd week,because she would feel like you did not want her for just the goods lol(no matter how bad she wants it wait a little, hard to get).
I think some girls think that if they have sex with the guy they like, he will like her even more.
I make sure the guy I end up dating is like a friend at first, we will play basket ball and we will do other not so close things, then I will slowly hold hands kiss,a back rub then sex!!!!!!!!!!!!!(dont want to seem sluty)
I date long term, I have not had a short term relationship,because I think of all my boyfriends I have ever dated as potential husbands,this might be weird but I have always wanted to get married and thats why I have long relationships to make sure I get to know them really well.
Sorry for going on and on.