It is always easier to avoid a problem than to try to clean up the mess afterward. If you had gone to the court at the time of the divorce and told the judge your situation, the judge probably would have thrown out the divorce proceeding.
Your ex should have stated in her Petition the date of marriage. It would be interesting to know how she handled that issue. Even though you lived with the second woman for seven years, if it was in the state of Missouri, your don't have to worry about it being considered a common law marriage, as common law marriages were abolished in Missouri in 1920.
If you had children with the second woman, the court can issue orders concerning their custody and support, whether you were married or not.
What you need to do now depends upon how long ago the divorce was entered by the court. Different procedures are used during different time periods. One thing is certain - you should have a lawyer try to get this straightened out. This is not something a pro se litigant should attempt. Good luck to you.
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