DH is taking me away for my birthday at the end of the month and his mum said she would have the kids. Great! All sorted. I mentioned to DH that we could get DS a toddler airbed for when he stays at grandmas and he'd be so excited. And DH was like " 
But they'll be here?!" It turns out that it's been arranged that MIL will be staying here in our house while we are away. I told DH hell would freeze over before I ever allow that woman to stay in my house unsupervised.
Now, there is a huuuuuge backstory. MIL is overbearing, interfering, controlling and I see her as little as possible. She kicked off when we booked our wedding (told us we were stupid and it would ruin our relationship), after our DD was born she told us we couldn't have any more kids, so naturally she kicked off when we announced DC2. She went mad when we put in an offer on our house because she hadn't viewed it yet (DH had to book another viewing just for her 
) When I was heavily pregnant with DD she offered to do a big clean of our house because I was really struggling. She told me to go out so I wouldn't be in her way so I obliged, came home and she'd rearranged the kitchen. I'm 99.9% certain she rummaged around in the drawers in our bedroom under the guise of putting laundry away as things were disturbed in bedside table drawers. On our wedding day she gave DH a card, told him not to show me and to open it the next day. It said how proud of him she was and how thankful she was to him for giving her a granddaughter. And that she wished he would get me to do more housework because he works hard and deserves a nice house.
When we moved into this house, we ended up having DHs brother living with us for 3 and a half YEARS (still kicking myself now for putting up with it for so long). He finally moved out a month before lockdown happened last year (thank god!!) he was living with us all through my second pregnancy and when I was 5-6 months, I had a go at BIL for leaving a mess on my freshly scrubbed hob. Next day MIL calls me for 'a little chat' and in a nutshell, paraphrasing slightly here- she told me I had to be BILs skivvy, I'm lazy and disgusting for not ironing and I have to lose weight. Same pregnancy, around 30 weeks-ish, she told us she had bought DS a toddler bed bearing in mind he was still in my uterus at this point. The bed never actually materialised so we're not sure what happened there.
Anyway, I don't want her to stay here. We DON'T have a guest room so the only place for her to sleep would be in our bed. Honestly the thought of this makes me feel sick. It's my home, my bedroom is my safe space. I don't want her tainting it. DH says it would be easier for the kids as all their stuff is here which is true tbf. But it's not like her house isn't child friendly and it's plenty big enough, DD has her own bedroom there!
WWYD?? I'm conflicted because I know it would be easier for the kids. But the thought of that woman invading my happy place is really upsetting me 
TL:DR AIBU to put my foot down and not allow a woman I can't stand to stay in my house and bed?