My brother and his wife harassing me and my parents.

My brother gets married intercaste to a girl three years ago after they get married my father didn't accept them because her parents did police case on my brother and also they harassed us because, they think that we support their daughters marriage with our son but that's not true at all. we are against this marriage due to some reason. so, they live far from home for first two years, last year due to my grandmother convince my father to bring my brother back to home, so they come to my home to live with us, and my father also accept them, but, now she(brothers wife) is behaving very bad with my mother and me, and now she is tell my brother to again live separately from my family and also she told my brother that he should not spend or give money to us. And my father is not aware about this because he goes at work early in morning and return to home at night and we are not telling him all this harassment happened with us because we don't want to hurt him, also not increase conflict.