My 40-50 year old uncle lives with my grandparents. They're 87 and have dementia but can do for themselves with our support. My uncle lives with them, he doesn't pay bills, occassionally (like once a week or less) cook food for them, doesn't buy toiletry or household items but works fulltime. He's not their caregiver, my mom and I do that. He has his girlfriend spend the night a few times a week. My grandparents don't like of course. It's their home, his and mine childhood home. I've asked her to not stay the night anymore and she continuesto stay. I've asked my mom aunt to say something to my uncle and they both won't and want to stay out if it. They're all afraid of him and scared to upset him. I plan to say something to him but I want to know their rights. They won't take much action because my grandma adores my uncle and wants him to stay but wants the girlfriend gone. Should I do anything to mitigate this situation if there's anything that can be done?