Although I do know of some women who have two male life partners, it is still the last taboo as you have said, because we live in a culture where the man is expected to "control his woman" and to have most of the power. Women are "supposed" to put the interests and needs of men and children before themselves, so they have no business considering their own wants and needs by involving another man. It never occurs to a lot of people that some men are quite happy with such an arrangement and don't feel disrespected by it (or whatever the narrative is). Anyone who thinks we don't actually live in a patriarchy isn't really paying attention.

Good article!