I'm sorry, EthicalsAngel, but I have enough reasons to question your motive or credibility:
1) You claim you're going to be a lawyer, yet you have trouble verifying a claim by your supposed bf? Why would he know the law more than you?
2) What's up with your grammar, especially if you're truly going to be a lawyer? (I suppose you're a law student at the moment.)
3) You are 23 years old, have kids but are lingering on the question of sticking with a man married before and playing games?
Even if your question is genuine, it's a travesty to see a woman at such young age not seeming to think she deserves someone better. You always second guess yourself, don't you?
If you really want an answer to your question, let's do it this way: What is your state of residence? What is the county? What about city? Actually, give specific information applicable to where your so-called bf got married, and his wife supposedly got divorced. I could see if it happens to be one of those with internet databases. If it is and you want a firm answer, then I could help you check. What I mean by check is to see if there's any legitimacy in his claim (i.e., that she was still legally married at the time) in the first place, unless of course the marriage took place overseas.
As far as my personal opinion: Such man doesn't deserve a good woman or any consideration even. He can do his explanation to himself or some fool willing to hear it. His a$$ would have been dumped since.
Edit: By the way, that's called bigamy! As far as I know, no state tolerates that . . . except maybe Utah. If his account is true, then maybe she married him in another state. It's easy for offenders to slip through the system when it's interstate.