The first thing you need to do is get to your local library and look up the state statutes concerning common law Marriage. It usually is determined by a set time period of living together in the same home. Also, if one state determines you are legally married, then you are in the rest of the states as well. If you have ever filed your taxes together, you are usually looked upon by the government as common law married. I would think that twelve years is probably well over the normal state time requirements. In that case, you will need to proceed with separation, divorce, and child custody in the normal manner. All of this should be done BEFORE you make any attempt to cross state lines. Even if you are awarded sole or even joint custody, moving without the approval of the court could result in a change in custody, in favor of your "husband." Make sure you know all the facts before taking this step or it may be detrimental to you and your children.