I wanted to know that we could live together, and the only way he was willing to consider this is if he could be away from the house 3 nights a week - regardless of which other relationship he was in at the time. He then admitted it's simply that even though we don't really spend much time together, he can't imagine wanting or being able to spend more, and it's better with me than with anyone else. He simply can't deal with being around someone every night, full stop. No willingness to compromise, which I respect if it's genuinely something he's unwilling/unable to work on. All our friends think he's going to regret it because ultimately we've been so good for each other, but I'm now just relieved to be out and no longer have to work around his hangups. Will miss him so much though
I can relate to him in this sense, and I don't think it's something that needs working on from his perspective. I don't see it as a dysfunction (you didn't use that word, but "something to work on" implies that you might see it that way... just my interpretation). That could be because my husband is the only person I can stand spending more than 3 days consecutively with. And at the end of his 3.5 weeks vacation at Christmas, I was sooo ready for him to go back to work out of town. I love him fully, I love having him around, but I need my own time and space. I think it's one of the reasons I never wanted kids.
I don't have OCD and I'm a psychologically healthy person, so I don't see that as a shortcoming in myself. I'm not sure this is a symptom of his OCD either, it could just be who he is. Someone having one disorder does not mean everything that's "different" about them is part of that disorder. Not every difference is a problem, unless the person with the difference sees it as a problem themselves.
What it does mean is that it creates a source of incompatibility with someone who wants / needs a relationship to be an "every day" kind of thing. So while it's not a problem for him in and of itself, it clearly is a problem for your relationship, and that sucks.
Now that you know this about yourself, it would be a good thing to put on the table at the beginning of any future relationships. Not like "Hi, thanks for asking me on this first date. So when do you want to move in?" but just mentioning that you're not interested in any relationships that don't have moving in as an eventual possibility.
I got dumped once because I told the guy we would never get married. I can't remember if that was when I still thought I would never get married to anyone because that meant being trapped in monogamy; but I definitely knew he was not husband material for me regardless. He was fun to date, but I knew it wasn't going there. For his part, he couldn't be in a relationship where marriage was never going to be an option. It had to be something that was at least theoretically possible. So we parted ways with no hard feelings, having learned something valuable about ourselves.