I understand the impulse behind that post about legalizing polyamorous marriage everywhere but the fact that marriage is so economically important and the fact that it determines which forms of long-term relationships are considered acceptable within society should make you question the institution of marriage and understand it as a tool of class society. We don't need to expand the institution of marriage so it includes gay people, polyamorous people, etc, we need to abolish marriage entirely and make it so that people don't need to be married to be economically or personally secure
In discussions like this there are always some people who say that marriage should just be for fun or if you want to do it, but you don't even need to wait for marriage to be abolished if you just want a "for fun" marriage. I personally call someone my wife despite the fact that we're both legally not married to anyone. The entire point of marriage is to serve as a legally binding contract wherein the state provides the married couple with certain economic and social privileges, but also implicitly or explicitly mandates they must stay together. It was designed to place women under the direct ownership of men, to keep women in the home where they are easily exploited and abused where nobody else can see it happen. It also has the purpose of separating groups of workers into easily moved small units overall lacking in external support which are dependent on the needs of Capital. It also has the purpose of transferring responsibility of the disabled from the state and society as a whole to an individual who is expected to care for their disabled partner, or abuse them as they please. If you want to have a "for fun" marriage you can just start calling people your husbands or wives, we don't need to keep marriage around for that.
