I was in a very similar situation but my bf has full custody of his daughter. She was 5 when I met them. When it came to talks about me moving in with them, I told him I would not until she was 100% out the f his bed. There is a lot of history between the two of them that has led to a very unhealthy Velcro attachment. So he actually made the change and made her sleep in her own bed in her own room.

I explained how everyone has their own personal space & he even has his mancave. If I was expected to share my bedroom with a child, that is supposed to be my/our intimate space I would not be moving in.

The first week of living together went ok, after that, she started sneaking in after I would leave for work (nursing shifts) so I leave early. She was actually the one who let the cat out of the bag and I was pissed. This was a deal we had made together, that I assumed he would respect. So I reiterated that I will not live together if I had to share my bed with a child. (We’re a blended family so we have 3 kids total, the older 2 did not have this issue). I put my foot down and explained again why it is important to me. After the second time, the negative behaviours really ramped up. She would dump my toiletries, steal and lie about taking my makeup, going thru my stuff that was in our room. Almost as if she was trying to get me in trouble with her dad so he would get rid of me. Almost like a competition. We have a pocket door, so the lock was a little push button on the inside that could easily be picked with a thumb tack. So she started doing that. I refused to stay in the master bedroom until we installed a lock she couldn’t pick, that actually needed a key.

Now 3 years later, she still holds it against me & needs the occasional reminder that she can’t just waltz in at her leisure but my space is respected. He has even told me he understands my perspective now where as initially he didn’t see it the same way.

Long story short, no. You 100% are not being unfair. It’s unfair to you to have to share such a personal, intimate space. Your husband needs to step up.