Hello Snowwhyte. On return to this forum after a short absence I picked up your thread. Firstly I would say that you are to be admired for the way you have coped and supported your grandparents so far with these difficult circumstances. I have also seen some very good advice from many contributors to this forum.
You say you do not like confrontation. I don’t think any of us does. But you clearly don’t like your current lifestyle either. There are times when we must be assertive to the point of risking a confrontation. Better to have a short-term bust-up than go on living long-term with a bad situation.
So let us examine the subject of this thread - a new kitten or two. It seems to me that it is your uncle that wants the kitten. Grandad clearly has the sense to see that this would bring problems. Uncle is bending Grandma’s ear because he is playing the numbers game; he is looking for backup. She is not mentally in a fit state to make a sound decision on this. Her expressed desires for a kitten are probably based on her happy memories of pets she has had in the past. She won’t see the potential problems now, let alone be expected to deal with them.
To bring a kitten - or, worse, two - into this situation must be an absolute NO, NO! You say your dog is aggressive. Consider also that dogs are territorial animals. You dog happily accepts the cat that has been its resident companion for years, but is likely to reject a newcomer.
So tell your uncle what would be likely to happen if he got a kitten. No ifs or buts or conditions. No “I’ll leave if you get one.” (You can leave anyway, but probably not at a moment’s notice; it takes time to find new accommodation.) Tell him that if he brings a kitten into this situation you’ll report him to the RSPCA. And be prepared to do it if necessary. Bringing a kitten into this situation will almost certainly warrant such a report.
Speak to him calmly and firmly to make your point. If he flies into a strop, walk out on him and give him a couple of hours to cool off. If he is as lazy as you suggest, he is probably too lazy to put up much of a fight if challenged. However one advantage of his living there is that if your grandparents were to go into a care home, the council could not sell the house to pay for the care.
Next you need to consider how to make a gradual and organised exit from this situation. As others have suggested, take “baby steps”. Take a fortnight off for a holiday, so that your uncle must cope, and maybe your cousin will cope better than you expect. It is certainly not too late for you to build up a career. But leave it another ten years and it will be more difficult, and you will have ten fewer years of life left.
Then there is the question of the will. It seems unfair that you cousin should get the entire house, when you are just as close a relative and have done so much in looking after your grandparents. I do think that letting your grandma die intestate is a better option than the one she proposes, though better-still options could be worked out. I agree with you that it would be simpler if all were sold and the proceeds divided up. Shared houses, other than by married couples, can bring problems. What happens if later one person wants to leave and others want to stay put, but are unwilling or unable to buy out the intended leaver’s share of the equity. You could find yourself in this situation.
Best of luck in the coming weeks but definitely NO to that kitten.