I'd like to add my own experience to the discussion.
Last June I had my first kiss and also my first lay with a woman at the age of 22. The natural conclusion I'm sure many of you will reach is that I'm goddam ugly--however, I would consider myself attractive, intelligent blah blah blah, and blame my lack of experience squarely on the fact that I'm fundamentally a social loner. Anyway, that is neither here nor there, I'm just setting the context.
So, I'm in a pub/bar with a close friend one night, after playing in a poker tournament. Also there are two other guys he knows, not very high quality, which i can clearly see in the way they keep getting brushed off by any women they approach. So these two guys try to get talking to 3 French girls, and my friend and I sort of interject and take over the conversation. Two of the girls aren't really much to look at, but the third is very cute...slim, brunette about 5'5. I can tell immediately that there's chemistry between the brunnette and myself. However, my friend is telling me about this house game he's heard of, and in the meantime the three girls have drifted off to another part of the bar...which one might interpret as a sign of disinterest.
So, we leave the bar and are walking down the street, when we get a phone call saying where this poker game is on...completely on the other side of town. We decide to go back to the bar and see if we can find the french girls again. So, we return, and see them outside smoking...we get chatting, and it's quite obvious to everyone in the group that the brunnette and I have sort of paired up even though nothing as yet had happened, apart from some hand-holding.
Anyway, we convince them to come back to my friends house for some drinks, and to play cards. So basically that's what we did till 5 in the morning. At this point I had made no explicit move whatsoever, whereas the brunnette had run her hand up my thigh whilst sitting on a couch etc. Looking back I should have done the obvious thing and tried to isolate her, bring her outside for some "fresh air", but due to my inexperience I sort of just froze. So the three girls eventually make like they're leaving...and I'm thinking to myself damn what should I do. Even when they're at the front door, I still do nothing. But , praise be to God, as two of them are leaving, the brunnette turns to me and says "I'm tired", and walks back into the house...and we both go up to one of the bedrooms. After that things took their natural course
The few things I think to be learned from this are
(1) Women can be sexually aggressive too, even if they don't make the very, very first move of actually striking up conversation
(2) Experience counts for a lot...at least in terms of confidence. When all this was happening to me my gut was basically telling me the right things, but I lacked the confidence and courage to act on that instinct.