I think he should not have started a living together arrangement with you. I am very messy and I just know that I would not be able to live with an OCD guy. Everyone should be aware of their limitations. Certain people are SO different that they cannot cohabit. Visit each other on a regular basis, fine, but not cohabit.

And another thing, these are very permanent traits. Love is changing: you can fall in love and out of love. But if you a clean freak, you cannot fall out of it. And vice versa.