My mother and step dad spend their days in separate rooms mostly. My mother barely speaks to him civilly. I have learned the term persecutory object. It is a case of this. Being like her in this way is (and has always been because she has always been like this) my worst nightmare, and yet I have become her manifested in this ultra specific way. I am kind and respectful to him outside of this issue where I am a raging B. But, mostly, I hurt myself in this because I mostly turn it inward and self harm, then give in to him. He is definitely doing his part though.
I managed to not be verbally and emotionally abusive in the ways that were done to me in childhood, not done to my children, went the other way, was so loving and kind, would never be mean because I love them. But I became what I hate most only with him.