It was put as a "we go in on this together and in 5 years one couple buys the other out and the bought out couple gets their own place." It seemed like a good idea until now. I don't want 5 years of having to hide myself

That's exactly how I feel. I don't want to pull him away from her either. I'm afraid I might end up alone if i set a boundary that makes him resent me or makes it an ultimatum. I don't want either.

He does say that if I don't want to move in with them then we won't, but it's always with a feeling of hesitation. Things with him and his mom are complicated. She died a few years ago and was revived and ever since then he can't seam to imagine a life without her in it. I'm not saying cut her off at all before anyone jumps there, I'm just meaning it as he adores her and loves her and can't put her at arms length now. He doesn't like how extreme she has gotten but he will humor her and let her talk however with no word of "that's a bit hurtful" or anything else. When she leaves the room him and his father jokingly say "Everything is the devil, (insert name)" and carry on as nothing happened.