Divorce petition adultery cruelty for Null marriage

As i have filed a divorce case on basis of adultery and cruelty against the lady as after 3 years of filing case .I got the proof that she is already wife of any other person.both opposite party against whom case i have filed is husband and wife.kindly guide my case has taken 5 years.as sec 13.1 i have filed against the lady and his husband .can we demand for null marriage in petition or file on more petition as filing one more petition will take time.as i have filed a criminal case against the lady and his husband 494 ,495 ipc as arya samaj marriage ceremony photograph and video graphy was introduced as evidence but judge neglected it and summon the lad y under 406 ipc is there any way to take advantage in civil matrimonial for null marriage.amendment can be done...