Seems like the biggest factor in women’s sexual interest equalizing to that of a male , is and always has been her being appreciative of something else the man has , could offer , or is doing, that is not primarily sexual. I am not saying it’s always phony and exploitive, or being a “ho”, but something besides sex to appreciate is a big part of the equation, like it or not.
Take for instance (post nuptial shut-off) PNSO , the woman was sexual while she appreciated the chance of catching that mate, or getting that first child, she wouldn’t be very disinterested all the time, couldn’t be. IF she doesn’t have,, or perceive, a lot to appreciate in that mate after the reproduction phase. It often becomes a declining thing or full stop.