My boyfriend, a married woman from his work..what would you do?

I don't understand why you're wasting one more minute on a guy who has conclusively proven to you that he is a liar and a cheater. What would be the purpose of keeping him as a boyfriend after this? You've been with him a month, and that was enough time to figure out what kind of guy he is. You've learned all you need to know here to get out.