Pretending basic biology doesn’t exist is so obtuse it’s dangerous. The sex with the capacity to make babies who are helpless for several years after birth face the constant threat of being saddled with the sole responsibility of childcare, and the majority of the physical burden of reproduction. A father’s biological necessity ends before he’s even lit a post-coital cigarette. A mother’s got to carry the kid for 9 months, and then push it out of a tiny hole (or undergo major surgery to have the kid removed). A father can opt in (or out); a mother can’t. No matter what social advances we make, none of it will matter if we’re barefoot, pregnant, and in the kitchen because we keep getting knocked up.