@Amar - Stalker is correct in saying if you listen to anymore of the scaremongering comments on here, it will make you feel even more confused.
It astounds me that Kalaiselvan has told you to contact a local big wig to get you out of this trouble. For what reason Kalaiselvan. This man has not committed a criminal offence. His actions of living with a married woman, who just so happens to be his second cousin may be immoral, but it certainly isn't criminal. In fact it is her who is committing the offence of adultery, and she is adult enough to know it - but of course, pathetic Indian law does not recognise that women can commit adultery. She is not only an adulteress, she is a control freak. She knows exactly what she is doing by threatening this man with suicide, and that ismental cruelty.
Amar, you must end this relationship as soon as you can. This woman will destroy your life like she has destroyed her husbands. Just do the decent thing and part ways as peacefully and amicably. I mean by making sure she is provided for and not just abandoned. Be brave and start afresh with someone who has no committments or a husband in the background.
Good luck and peace and love to you.