suspicion on husband and his employee

My husband and I are employees of a private limited company. I have strong suspicion that he had an affair with an employee. But he denied. I even spoke to that employee. Also my mother and sister spoke to that employee and now she is no longer coming to office for the past 2 months. I even followed then using detective agency but i got no good evidence. Now my husband has said he is going to file for divorce under cruelty because of my suspicious on him and making him lose an employee. The girl is also now saying she will sue me, my mother and my sister for criminal intimidation. What are my options legally, please help ?