Most males are rather clueless about women. I DO NOT understand women however there are some signs that a woman has some interest. If a woman is interested she will often mirror the object of her interest, if I turn to face her, she will turn to face me. If I turn back she will do the same. Eye contact is a biggy, if she makes and holds eye contact she is definitely interested, unless you have scared her. Physical contact is another sign, it doesn't have to be major contact a casual brush against his body more than once is a good sign. The biggest mistake a man can make is pushing the issue, let her lead. Watch your mouth don't be vulgar until you have an understanding of what she wants. Compliment her, tell her she has great eyes or something else the is flattering but neutral. This is not a time to tell her she has great tits. Back in the days before the group I would suggest going for a cup of coffee, if she says no I would tell her that I would like to see her again and ask for a phone number and the best time to call. If she declined I would offer my number. I was surprised when I gave out my number without getting hers how many women would call a day or two later. And then there have been a couple of women that have just indicated that time spent where we were was detracting from the time we could be fucking.