Most men don't realize this, but women fear being rejected by a man as much if not more than a man fears being rejected by a man.
When a woman gets rejected by a man she feels as much pain if not more than any man would feel.
This is the main reason why women rarely if ever approach a man and when they do it is usually a very subtle approach.
That way if she does get rejected, she can say he simply didn't pick up on my hints, thus avoiding the reality of being rejected since he simply didn't get it.
What this also means is that it is important for men to realize most women aren't going to put themselves out there and risk rejection at any point of the interaction.
If you don't risk rejection and she doesn't risk rejection the interaction and the relationship is going to go no further that where it is at if not end.
Most of the time what that means for men is a trip to the "friend zone"!
What makes it worst is that women usually are not attracted to men who act like them in terms of being afraid of rejection.
As a man, you are in control and once you allow the relationship to not move into the sexual realm it isn't ever going to go there.
Once the window of opportunity opens she knows and you know it; only she is perfectly okay with it closing and the two of you staying where you are or simply becoming friends.
She wouldn't mind if you took it to that next step, but only while the window is open and she isn't going to risk rejection herself to get you to go through it.
In the end, once you realize that women are afraid of rejection more than you only you can lead the interaction and relationship no matter what.