Same Sex Marriage and Bigamy - Permitted?

I’m wondering now what would happen if a group of people, all of the same gender, decided to live together and hold out to the general public that they’re all married to each other.

Probably not much, as long as no more than two try to file joint tax returns.

First, IANAL.

Federal rulings on SSM have, to the best of my understanding, depended upon 14th Amendment due process and equal protection arguments and not on Full Faith and Credit rationale.

Indeed your linked judgment comes to the conclusion

my bolding added

The court goes on to note that a SSM ban is a violation of equal protection rights.

So there are plenty of reasons that courts are using in their rationale to strike down SSM bans and bans of recognizing a lawful SSM entered into in another jurisdiction. But as far as I can tell the courts are not relying on a Full Faith and Credit argument.

Indeed the Wikipedia article on the Full Faith and Credit Clause claims in the context of interracial marriage bans that, "[t]he full faith and credit clause was never used to force a state to recognize a marriage it did not wish to recognize."

I’m digging through some of the examples cited at the end of that Wiki article (on the Full Faith and Credit clause). One involved whether a death certificate would be issued in Ohio listing the legally married gay spouse as the surviving spouse. Ohio law at the time prohibited recognizing same sex marriages entered into lawfully elsewhere.

Judge Timothy Black ruled (pdf link) that Ohio may not issue a death certificate that does not list the surviving partner as a surviving spouse. But he based that ruling on the SCOTUS ruling in Windsor and on the 14th Amendment. FF&C was not a part of his ruling. I’m not sure how that example got cited on the FF&C wiki article.

It was in the first paragraph:

If and when the law “evolves” to a point where the FF&C clause requires states to “respect” each other’s laws, you’ll be correct. Currently, that is not the case.

Also, if you go to the source article in wikipedia about the case in Ohio, you’ll see that it wasn’t quite what you think it was.