I think most people flirt as an outlet. We are social creatures and crave human contact, and there comes a point in every relationship that that contact is lessened, so we get it elsewhere. I'm not talking about physical contact only, it is the social contact as well. Like us talking on the forum, it is time out, it is socialising.
I think the point I am trying to make is that it is one form of escape, and I don't believe our partners have the right to try to control that, especially for me as a woman, I work full time, I study occassionally, I have an old fashioned partner who does nothing in the house, so I do it all. After working an 8 hour day, comming home to a couple of hours of housework and cooking, if I choose to talk to some friends on the net rather than fall asleep infront of the TV I believe I have that right, and the right to do that without feeling guilty.
It seems to me that the aim of control is to stop your partner from doing something they enjoy, punishing them.