Genes which allow females to be less inhibited leave fewer...

Genes which allow females to be less inhibited leave fewer copies of themselves than genes which persuade them to remain highly selective. Among males, the best strategy is exactly the opposite one. The maximum advantage goes to those males with the fewest inhibitions. "Love 'em and leave 'em" is not so much a nasty peice of male chauvinist piggery as an accurate reflection of biological reality.