When we get past the age of 18 we are expected to eventually move out of our parents homes and be self sufficient by getting and keeping jobs and managing our own lives properly and responsibly.
We are also given the messages by society that men are supposed to work and pay the bills, protect and defend both themselves and their loved one's and that it is ok for men to have sex with as many women as they can.
Women are historically taught to stay home, take care of the kids and the house and to be good wives and mother's. They are also taught that if they have sex with too many men, then they are considered by society to be sluts and that is generally looked down upon.
Much of this stuff is also rooted in our biology and evolution and dates back to prehistoric times when men and women lived in caves. The men would go out and hunt and fight other clans while the women stayed back at the cave taking care of the children.
For the man having sex with more than one woman was beneficial as it ensured the survival of the species. For a woman it was not in her best interest to have sex with more than one man as she needed him to provide for her and her children. For her it and the children it was a matter of survival.
Many of these instincts have stayed with men and women throughout the years and have merely taken different forms, but the basic concepts are still there and whether people like it or not, it tends to dictate how men and women tend to think and act.
