neighbors to a bigamist

We have new neighbors. Two women, one man, and 4 children live together. One man and woman are Mr and Mrs T... The other woman, who has a different last name, introduced herself to our other neighbor's 21 y.o. daughter saying she was Cathryn S... and this was her husband, Mr T..She also told someone "we have 4 children" and another time answered the phone saying the caller had reached the T's when she was talking.
Isn't this bigamy, even if Cathryn is a common law wife? I looked it up and in Montana bigamy is just a misdemeanor. Does that mean that the neighbors have no recourse but to put up with this "unusual family unit"?

Although this question was posted a long time ago, I thought I would answer it, since no one else attempted to.

How does what happens in your neighbors bedroom affect you? Although it would not be my personal choice, swinging is a choice that some people make. The man and woman, Mr. and Mrs. T are MARRIED. This means it is legally impossible for Mr. T to be married to anyone else. Whether the other woman calls herself Aunt Jemima or Mrs. T. is irrelevant. Legally, she is NOT common law married since Mr. T is, from what you have said, legally married. You cannot have a common law wife and a legal wife.

If this arrangement offends your sense of morality, consider that you might do things THEY don't like---like eat meat, or gossip randomly with neighbors (ahem). What they are doing, unless they are fraudulently obtaining government services or something like that under false pretenses, is NOT illegal. Mind your own business. Because what is acceptable morally to them is not to you doesn't mean they are bad people or bad neighbors. Now, if their lifestyle interferes with the quiet enjoyment of YOUR life, home, and property, then, perhaps you have legal grounds.

Surely something in your own life requires this level of rapt attention as your neighbors sleeping arrangements?I had a neighbor that insisted to everyone he was Jesus Christ (seriously!) The dear old man didn't have a clue. Instead of having my religious sense of propriety offended by this poor guy "posing as deity", and ask hellfire and brimstone rain down him, I greeted him, became friends with him and missed him sorely when he was gone. Broadening your horizons and learning tolerance does NOT jeopardize your own rightfully held moral beliefs. Live and learn.