Why would virginity be attractive to our hunter-gatherer forebears? Until the recent invention of DNA testing, a man could never be sure that a child was his. Mothers could be damn sure they were related to their kids, but men had no “paternity certainty”. In evolutionary terms, spending time and resources feeding and protecting offspring that will not continue your own genes is a costly mistake. And humans have thus evolved behaviours to prevent this: jealousy, possessiveness, mistrust, and most unfortunately, the oppression and denial of female sexuality. Its modern effects are seen in “slut-shaming” and FGM, victim-blaming after rape or assault, revenge porn and religions that venerate chastity and punish those who have sex before marriage.
I’ve always found it amusing that it is the left which rightly insists on the truth of evolution but also the left which so rages against the behaviours that evolution has left us with.