AITA for not wanting to turn my baby's nursey into a guest room for my MIL?

Me and my partner are expecting our first child. We live in a 2 bedroom apartment abroad, thus far from both our families.

The "spare" bedroom is currently used as an office/deposit, but we are slowly turning it into our child's nursery.

With the baby coming, both my family (parents and brothers) and my MIL will likely come visit us more often.

As of today, we do not have space for them to sleep with us, thus they will need to arrange accommodation in an hotel/Airbnb.

For my parents this is perfectly normal and reasonable, while I feel some resistance from my partner when it comes to his mother, likely because she would be travelling alone hence her costs would be higher.

He keeps proposing to buy a bed for the spare room/nursery, even after I have repeatedly told him that a) a bed won't fit once the rest of the baby's furniture is also in the room and b) a nursery can't be a guests' room at the same time cause it would disrupt the baby's routine and be uncomfortable for us as parents having to go in all the time.

He insists that it would be useful for my family too (he never directly mentions his mother) while I already told him that my family has no issue staying in a nearby hotel/Airbnb.

I proposed changing the living room's sofa with a sofa bed, but I also stressed that at this time and with all of the expenses we have I do not feel like this is a priority, given that we have a nice and expensive couch already. Also, if I know anything about his mother is that she would not sleep in the living room, so I would be expected to give my bed to her instead.

Now my own mother is making jokes ​that I just don't want my MIL around, which annoys me because I am somehow expected to turn my home into an hostel while my priority is preparing for my baby and getting to the end of this pregnancy safely.

My MIL is very wealthy so I don't have any compassion for her having to spend a couple hundred euros once or twice a year to literally visit her only grandchild.