DOMESTIC VIOLENCE

Sir husband of my cousin sister is in illicit relationship with other unmarried girl from many year. This has come to her knowledge recently when some objectionable photographs and train/flight ticket proving that both are travelling many time together in India and foreign. Now, her husband clearly saying that he will not living with her and want to divorce. Sir My sister have two daughter 14 and 8 years respectively. Since their activity come to my family knowledge he did not come to the front and not telling address where he is working or living. The alleged girl is a bihar government employee in health sector. She recently went foreign with my husband without consent to her office or family. My sister do not want to give him divorce. Sir please suggest what action could be taken to save her and her children life/future.