Generally speaking, I'd agree with Fran on this, but there is one thing you should you. Technically, if you and he were no longer living together at the time his divorce came through, your "marriage" to him never became valid. If that's what happened, what you need to do is not get a divorce, which you an only get if you were actually married, but instead get a judge to declare your marriage void--which just fixes the legal mess you may be in otherwise.
If his first marriage ends then your marriage becomes valid.
So get a divorce.
Fran Brochstein has over 20 years legal experience & enjoys educating the public about Texas laws. She is a full-time family law mediator in the Houston area. If you found this answer "helpful" or "best answer", please select the button to show your appreciation. Please understand that this is not a personal consultation and in no way creates an attorney-client relationship. You are strongly encouraged to consult with an attorney in your county in person about your specific legal problem. You can contact her at 713-805-9591 - 7 days a week - her personal cell phone.