If you want to travel on a childish path that you mnarried him first so your marriage is legal and marraige with her is void. The stand corrected:-
- If he knew that he was alreayd married and cuased that lady to marry him hiding the facts then is is guilty of cheating..
- He knew that he is already married and his marrige with othr lady would be void still he had hidden the void nature of marriega and cause the lady to believe himself to be her lawful husband and had s*x with him. He gets guilty of rape.
Do not think you to be safe. You can be alleged to be onlooker with connivance that your husband gets into fraudulent marriage and extracts a dowry and them comes back to you.