Quick Definition: Keeping in contact with a woman and becoming her long term friend.
A friend close is an alternative to full closing or exchanging contact information with the intention of hooking up or dating the other person immediately. This is a great way to build up a circle of genuine friends, instead of trying to full close every girl you meet.
Sometimes you still have chemistry with a woman (as any dominant man would), and she may be in a relationship, married, or otherwise unavailable. Or, you may be in a relationship and unavailable. Exchange contact and keep in touch. Remember that friendships have other benefits. In case something happens, you always have another choice or option. Ironically this also makes your current relationship healthier because you are constantly making the decision to choose your GF over another girl. Sometimes, genuine girl friends can introduce you to their girl friends and hook you up with an endless supply of potential dates.
Another way to friend close a girl is to offer to give her advice on dating men: “You can use me as a consultant. You know, for explanations into the male psyche.”
Interesting news story on female friends after marriage