Get the State out of the Bedroom!
Same-sex marriage and Mormon fundamentalism are, of course not-so-strange-bedfellows. If you accept the former, why not the latter? But, in a non-nation like America, that is not the point.
I don't give a damn whether Barack Hussein Obama or Andrew Cuomo recognize my marriage; I have no say about their conjugal unions, other than to acknowledge that at least the federal functionary seems to be keeping up appearances, or anyone else's. Polyamory may have its allures for some, but I have enough trouble with just one wife. Don't expect the rest of us be taxed for your troubles.
Sex workers? Just keep your profits off the books and untaxed. Don't expect the rest of us to legitimatize your profession, however old it might be, and offer it as a legitimate career option for our daughters.