If women worked in the fields tending crops while men hunted animals (in wooded areas), it could actually work out the other way around in terms of exposure.
In any event, its not clear that phenomena can have an evolutionary basis. Regardless of the perception of sexual gender in a potential mate, if the other is in fact of the same sex, there is no procreation, so its not clear how the selection mechanism would be operative. There are (to be polite) far more suggestive indicators of sexuality in the human body which are fairly readily apparent and far less prone to miscommunication.
In any event, its not clear that phenomena can have an evolutionary basis. Regardless of the perception of sexual gender in a potential mate, if the other is in fact of the same sex, there is no procreation, so its not clear how the selection mechanism would be operative. There are (to be polite) far more suggestive indicators of sexuality in the human body which are fairly readily apparent and far less prone to miscommunication.
http://www.youtube.com/watch?v=kRopmfinsWk