Oh Logan. I didn't realize this was going on and am so sorry to hear it. My first thought was that maybe Butter senses that Mimi is not well and is taking advantage of her. I really didn't even think that I would offer that up as a suggestion but when I read rosethecopycat's remarks I thought maybe it is worth pursuing.

Maybe she is just fine physically (I certainly hope so) and Butter is just sensing her slowing down and is throwing his weight around. I really have no thoughts that would be helpful but I just wanted you to know that I am worrying right along with you. Mimi has been a favorite of mine for years now; so beautiful, dignified and such a long time companion for you through all of your life challenges. I do hope there is an answer out there. If anyone can help you, PTers can. (((hugs)))