Me, I could care less who sleeps with whom and with how many....not my business. But I do have a problem when it involves kids or people under legal age.
I dont' claim to be smart enough to know what is right or wrong when it comes to the beliefs of someone else...that's their business not mine.
So I see it like this...if they are happy, not breaking any laws( I know plural marriage is illegal...but aside from that), contribute to society in a good and successful way, raise their family and they are not wanting....live happy and prosper is what I say!