Marriage Between Two Married People.

I have been seeing One Married Woman Having an Affair with another Married man. Woman isn't legally married. She was married to her husband when she was 17. It has been more than 15 years now and she is having this affair since past 5 years. she is almost 29 and has 12 years old daughter. The man she is having affair with has a 7 years old son and is legally married to his wife. His wife is not giving him divorce since past 6 years. She wants his money and property and mentally tortures him and tells him to stay away from his parents and buy her gold (a lot), fights everyday over petty issues. He was fed up of her behaviour after giving her several chances to be a better wife, she isn't helpful. She is also telling him that she will file some weird charges against him and destroy his life if he ever tries to file a divorce. Now on the other hand, the woman he is having an affair with has a husband who is alcoholic and abusive. Now the man and woman are planning to get married but the man wants to do it legally or anyhow. Man's wife wont give divorce and I guess since Woman's marriage was never on papers and they have no proof of getting married in first place they dont need a divorce. Is there anything they can do so that they can get married, or anything he can do to get a divorce or any other way that you can suggest. I am seeing this couple having this extra marital affair since past five years and now they are crying cuz of abusive partners they have and I am worried one might end up losing it's life. it has been a long fight for these two now. please help.