Mental Harrasement

Dear Sir, We are a joint family in Delhi, we live with my in-laws n my sister in-law(husbands sister) and we have two kids. My husband works with his father and we live in house which is owned by my father in-law. My father in-law thinks, Me n my husband are trying to stop my sister in-law from getting married, as if we do so, later on in life all the property can be passed to our name.As if my sister in -law would be unmarried, why would she need any property. My father in-law has no proof or evidence which supports his doubts, but he keeps giving torturing comments and tells us to leave the house.Currently we are not in a financial situation to leave the house and live separately. But my father in-law has spoiled the peace of mind and even has started sharing these things with people outside home. This is highly humiliating, please tell us a way out of this. Is there is a legal section against such humiliation and we can give some notice, which scares him and he stops humiliating. We have even given him a letter in writing which mentioned that we are not interested in any of my father-inlaw's properties and he can donate it to any trust, but that also didn't help. Looking forward for your prompt response.