Here is a New York Times article that gives lawyers and judges one more thing to chew on in child custody cases.
A Texas court enforced an order prohibiting a same sex couple from living together in Texas with the children of one of them in the home. In Texas, they can't get married, so the court enforced a morality clause in a divorce agreement to keep them apart when the children were present. According to the story, such provisions are typical in that jurisdiction.
The last time I saw a judge in California make such an order in a case with two people of opposite gender living together has to have been 30 years ago. Occasionally there will be delays in allowing such arrangements for very young children, or when the separation is fresh, due to the impact on the children emotionally from seeing one parent moving on to a new relationship. But, in general, California judges do not consider this type of conduct to be very serious. We see few cases with same sex couples in this situation, but I doubt the rulings here will be any different, but it will be interesting to watch, no matter what side of the argument you are on.
Decades ago, I had a client move to Missouri with her children. Despite a court order from California to the contrary, she was able to get a judge in Missouri to prohibit visitation to the father because he was living here, in California, with his girlfriend. The consensus here was that the Missouri ruling was "quaint." That was the last time I had experience with such an order. Things are different here.