We live in a 4-bed house. My husband and I have a 15 year old daughter. My husband has two children in their 20s from his first marriage.
We purchased this house 15 years ago, when I was pregnant and each of the children had their own room. It still remains that way. My step-son visits regularly (roughly fortnightly) as he and his Dad have a hobby they pursue together. My step-daughter visits once or twice a year, sometimes staying overnight (maybe two nights if she visits at Christmas). Both my step-children still live with their Mum about half an hours drive away. Neither of them keep much in the way of personal possessions here. My step-daughter has nothing and my step-son only has a few spare clothes. Their choice, nothing to do with me.
I was thinking that I'd actually like the smallest bedroom as a room for me. I have lots of books, enjoy crafting and would like a space where I can leave out half-finished projects. I could also use it as an overflow for my clothes as our bedroom storage is small. My husband uses the study downstairs to work at home (I work full time but outside of the home) so he has "his" space for all his gaming and techy stuff.
Would it be unreasonable of me to "reclaim" this room from my step-son? My step-children are very rarely here at the same time (maybe every other Christmas for a day) and we would still have one room available for them. If they both wanted to stay, I'm sure we could muddle by for one night, with someone on an air bed in the lounge (happy for that to be me).
Should it be expected that we keep two rooms available, at all times, just in case of a visit from my step-children? AIBU to suggest this to my husband and expect him to agree?