Your adult daughter has been married about ten years, she and her husband have a couple kids. Bigamy is decriminalized, and there is no longer any civil penalty (as in divorce) for adultery.
Your son-in-law brings home his next "bride" to share the home with your daughter and grandchildren. Your daughter finds out that she has no legal means to kick out the new woman, and not only that, but her property has now been diminished because community property would split it three ways. So even a divorce wouldn't help her much.
It'll happen . There was a reason that marriage was defined the way it was--libertarians think they can just willy-nilly make the world adjust to their philosophical whims...
The one that doesn't is Islamic polygamy, in which wives are chattel and a husband can acquire a new wife in about the same way that my neighbor adds a new cow to his dairy herd.
Your nightmare scenario assumes my daughter is powerless and a helpless and subservient pawn of her husband. Luckily, I did not raise my daughters to be those things.
Yes, and the reason was to prevent the good providers from soaking up all the potential wives, allowing an underclass of unmarriagable males to be created.
In the absence of legal prohibition, polygamy will most certainly happen here.
Ask any married man with a job how many women have expressed an interest in an exchange of services.