One does visit your Dad once or twice a week?! I would be over the moon if one or both of my older two adult kids came (or just stopped by to visit) once or twice a month. How about a year. I'm sorry, what is it you expect that one to do? You may not have meant for it to all end up on you, when you moved in with Dad, but that's apparently exactly how your two siblings are taking it. And likely, they're very happy about it. My youngest lives with me too, and I don't even have a cognitive disability. The only way I ever get to talk to (just one) of the older 2 is if I call him. Then, I get, at most 5 minutes before he has to get off for something. He's used "baking cookies" 3 times, just in the last year. He's used dinner is ready, He's driving, it's endless. My sister told me to just accept that it's gonna be fore 5 minutes, each time, at most.

I had an aunt with Alzheimer's and her (only) two adult children, found out she had that diagnosis and they put her in the nursing home, sold her house and everything she owned (almost). That was back in the 80's. They sold everything they didn't want of hers, spent, or put in a trust fund every dime they could find of hers, and I think that was about the last time they saw her. One of those boys of hers was a Lutheran bishop! Then, people wonder she stopped knowing her own relatives when they went to visit her. My Dad faithfully dropped by, no matter how painful it was on him. She died 20 years later. It's horrible just to know about it, firsthand.

Your Dad, and your Mom are lucky, and mightily blessed, to have you. The one who stops by once or twice a week, if you need him to do something, tell him so, and be specific. Maybe that's all he needs, a little directness. Or...maybe the visits are the best he's going to do. For your Dad's sake, accept whatever he'll give.

Some of us would be enormously grateful for weekly, monthly, or quarterly visits in person. And so would the adult sibling who otherwise gets no one outside the home to talk to, that knows part of what's going on. The one who won't listen to what's going on with Mom, I suggest you find an ear to bend outside your new/old home with Dad. It's not just them who needs to know it, you need to have someone to talk to about it. Like a senior in your church, and old friend, or even a kind social worker. God bless.