Could you live with you mother in law

Basically my partners nan is old and ill when the time comes his talking about him mum living with us getting us on the property ladder (we rent ) I told him I don’t want to and his kicked off his talking about us all living in a 4 bed he has 2 other siblings too I said I wouldn’t like to for many reasons I’d just link to live in my own house with my own comfort his mum his quite high maintenance as is she doesn’t like cleaning products or candles as it give her headaches so I would be told I can use them he dog really really moults and I’m not good with dogs that moult also my mum and really bad allergies so wouldn’t be able to come round by the way. We are dog lovers but my mum has poodles they don’t moult And now because I’ve said no his just being horrible and stubborn and I’m not going to lie when I say I feel like I’d be so miserable living with her I can’t even explain and I don’t even mean it in a horrible way I’m genuinely so worried that when that time comes I won’t have a choice and it will just happen without my say She’s not horrible but we are just very different people and she just someone that I couldn’t live with literally feel like it would bring me into a break down if I lived with her Now his not talking to me told me it’s my daughters future at risk because will just be renting forever Said I’m nasty and if my mum ever in the future need to move in he will be really nasty and be like no it’s no happening just being really horrible to be because I’ve expressed how I feel and why I wouldn’t want to live with her nothing in a nasty way I’ve been with him 13 years in that time she’s cooked for me 5 times doesn’t like hovering or anything like that when we meet she would take all his wages every Friday to the point where he paid her Morgage there’s so much to it I can’t even explain I don’t hate her I’m just not her biggest fan and now I feel like I’ll have no choice and I’ll spend the rest of my life miserable