"Vulgar?" A woman having more than one husband, "vulgar?" No more so than his having more than one wife, IMO.
Besides, I have news for him and any other polygamist out there: if their "lifestyle" ever gets recognized by the mainstream, polyandry (having more than one husband) will be right behind it. On what basis would you deny a woman the right to be married to more than one man, if you give the right to a man to be married to more than one woman? The men don't like it?
I don't favor either one. And as far as the "Sister Wives" folks, I want to just tell them to shut up and sit down. Nobody made them choose their "lifestyle."