Free sex is the product of a mature society
In which primary needs are largely addressed, if not through abundant employment, through welfare and social services. You may find a lot of the girls who want to have sex with you have no reason to ask for anything in return. Our society today is hyper-obsessed with gender, a sign that life has become very easy Life used to be messy, rough, and short, so that there was little time to spare for any endeavor that did not contribute to one's survival. Sex alone does not lead to one's survival.