Legal Question in Family Law in California

You can ASK your spouse to do anything. There is nothing stopping you from asking. But there is no legal basis to prevent him to not introduce his girlfriend to anyone he wants.

As far as naming his girlfriend in the divorce -- the only people who can actually be parties to a divorce are the husband and wife. But it might or might not be relevant to bring the girlfriend to the court's attention, depending on the circumstances, and on what you are trying to accomplish.

It is not illegal to ASK anything, unless it is soliciting a criminal act. It is also not illegal for him to refuse.

Mr. Crowder is not entirely correct about the girlfriend in the divorce. Because California is a no-fault divorce state, the girlfriend is irrelevant to the proceedings unless there are children involved and she is a Child Protective Services level threat to their safety or well being. Some family court judges will sanction you for trying to inflame the proceedings by bringing up irrelevant new girlfriends or boyfriends.

I agree with Mr. McCormick. There is no reason to add the girlfriend to the case unless she has an affect on child custody, or has property in her control that belongs to the married parties.