Harassments after Divorce

Respected distinguished Advocates, My Father who is presently of 58 years (also a patient of cancer) has given divorce to his first wife in year 1987(one sided divorce given by magistrate). after 2 years of his successful divorce my father married with my mother in 1990 and lived a peaceful life till 2015. In year 2015 my father's 1st wife filed a case for maintenance in MP district court. and the court passed a order in her favor of 10000 maintenance per month. My father challenged the lower court order in high court and till then the case is in high court of MP. But in meanwhile my father's first wife and the son(of 32 yrs of age who lived with her mother after separation) has ashamed my father and my family in our society and also in the office by false allegations and sayings. They r threatening us and my father that they could file enormous case against us for property and money, as they are well aware of that my family is already facing much difficulties in treatment of my father and in addition to that we could not bear the further load of these court hearing and all. Now in this all, pls help me what we can do such that we can not face any further humiliations. please provide me your concerned advice.