Urgent advice requested

Dear Experts, I am caught up in a peculiar situation. I hope I can be honest in putting down the situation clearly. Background: Almost three years ago I had suggested Mr. X not involve in controversy with Mrx Y in presence of some of the colleagues, as I was head of the department then and Mr X was my student with a favor ands colleague. Mr X had come home and had fight with me about this remark/suggestion. I told him plainly that I told you as the people in department commented, and as a senior in good faith I told you to avoid. He used to comment similarly about some girls. I stopped talking with gentleman Mr X. Present Controversy: Me and few of my colleagues have a feeling (as those who have seen don’t want to accept), that of Mrs Y has put proxy initials of Mr X for few days. It is evident from the change in signatures. Both have an apprehension that I have complained about it and there is a group which has done it. Hence, they together enquired about this with few of class 4 employees who move with me. Husband of Mrs Y has threatened of police to a person who is close to me and used to work before. Now 3 days ago, Mr X, Mrs Y and husband of Mrs Y visited my house and had arguments over it. As I didn’t make complaint I didn’t accept their allegations. In the course of discussion and incident with my friend it appears they have received phone calls and/or sms regarding the character of Mrs Y. Mrs Y used very slang words and threatened me of mahila police and suicide etc. My wife and son were also present. It was evening 715pm onwards. The husband of Mrs Y is calling me and few of my colleagues at odd hours. Hope I am clear about the situation. Please advice me. Thanks in advance.