My mom is 88 years old and lives with me and my son and his wife and a grandson. I have a nice man I'm dating and have been for over 2 years. He has never said or done anything out of the way to my Mom but anytime he comes over to see me she is rude and makes remarks like "Why is he here" and if looks could kill kind of looks.I Tell her that is not nice and rude to say and tell her to behave herself and stop with the dirty looks. She has Vascular Dementia but early stages of it and for the most part acts fine other then not remembering certain things now and then. My friend has always said hello to her when comes in and has even brought her flowers when he brought me some ot not make her feel left out. Is this jealousy or what? I try to ignore it and he says it doesn't bother him but it bothers me and embarrass's me when she says things like that. He is the only one she is like that with! I don't get it.
I'd try to remind your boyfriend that she has dementia and can't be held responsible for her behavior. As she progresses, it could change and she may forget that she ever disliked him.