[nathan_f77]

> For some people, marriage is more than a financial arrangement.

For sure, but you don't have to tell the government about it. You can still have a ceremony and wear rings and swear you'll live together until you die. Informally, you can pretty much have whatever kind of marriage you want, even a polygamous one. No-one is going to stop a bunch of people from living together as roommates in some kind of committed relationship. Although I just checked, and some of these relationships are actually illegal in Canada [1]. I think it's really just to protect minors, and they don't care what a bunch of adults are doing.

EDIT: Haha I also just noticed your username

[1] https://en.wikipedia.org/wiki/Legality_of_polygamy#North_Ame...

[Houshalter]

There's no federal law against it, but many parts of the US have laws against "unlawful cohabitation". Which is the main tool used to enforce the ban on polygamy. The laws could apply to unmarried couples that live together, but have only ever been used against polygamists. The supreme court recently turned down hearing a case to overturn such laws, keeping the practice illegal: http://www.sltrib.com/home/4848475-155/polygamy-remains-a-cr...