Pareto's sex rationing

I read a few years ago that male sexual activity displays something like Pareto's principle: About 20 percent of the straight men get 80 percent of the sex.

That means that the straight guys in the 80 percent fraction of the male population have to compete for the scraps and leavings in the 20 percent of the sex women grudgingly offer them. I say "grudgingly," because these women consider the 80-percenters second, third, fourth, etc., choices as sex partners.

That could explain a lot, and not just my situation. It could also explain my father's apparent absence of a sex life until his early 30's, despite what Alfred Kinsey's research showed about American premarital sexual activity in the 1940's and 1950's; and then his having to marry an unattractive woman like my mother.