Marriage is weird man. Why not just legalise polygamy. If that kind of stuff can "tarnish the institution of marriage", then maybe marriage was a weak instutution to begin with.
And they should legalise sex cults too. I mean honestly, besides being cult leaders what did David Koresh or R Kelly do that was so horrible? As far as i'm concerned, the only thing they are guilty of is running a sex cult. And the only "crime" committed by Alison Mack was the crime of luring young girls into a sex cult. One you get rid of the sex cult stuff, suddenly they don't seem so guilty