The first wife's divorce is the first wife's problem.
You can file a motion to have your marriage declared void, which you should do ASAP. If you don't do that, then as soon as the first marriage is dissolved, your marriage will spring to life and you will start accumulating community property that you might have to split with him one day.
File your motion to declare marriage void ASAP and get him out of your life.
You do not need an annulment because you were not married to him. One cannot be married to two people (in Texas) at the same time. The second marriage (according to Texas law) would not be a marriage.
You should ask the question under Las Vegas to see if it is different there.
The wife in Milwaukee needs to file for divorce and have him served.
I am a Washington attorney and have no knowledge regarding the laws, rules or procedures in the State of TX. If your situation was occuring in the State of Washington, my answer would be as follows:
When you say he skipped out on you "and the kids" do you mean your kids together or just your kids? Fraud/bigamy is certainly a basis for annulment. As for prosecution, I'd call the county prosecutor and see if they're interested. Since he resided in your state with you, it sounds like there may be sufficient personal jurisdiction over him there to prosecute him.
I highly recommend you confer with an experienced family attorney in your State about this.
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