I agree with Anne. Even two people with contamination obsessions could clash badly. I have a friend who has exactly the same fear as me, but the way in which we deal with it differs greatly and there is no way we could live together.
I have also noticed that when one person with OCD is doing better they can become more impatient and intolerant than a person who has never experienced it. I’d like to say this is unusual, but I have found most with OCD react this way. A case of ‘if I can do it, you can!’.
I had one friend who was really nice when his OCD was severe, but he could be uncaring and abrupt when he was doing better. He attempted to become my therapist and almost drove me mad! Other friends with OCD have also been harsh and judgemental, one stated I am pathetic. I have reached a point where I am prepared to listen to other's problems, but prefer to keep mine to myself as much as possible, for fear of being hurt very badly.
I think the ideal relationship for someone with OCD is a person who is not a sufferer, but who is compassionate and patient. My husband has a short temper, and that has been a recipe for disaster. As Anne also said, reassurance can be detrimental, but being too forceful and impatient is even worse.
Obviously it’s possible for two people with OCD to form a relationship, but I would imagine it rarely works out. I have a friend who is in this situation and I could write a book about her relationship. The simple chore of shopping has sparks flying, because each feels strongly that things have to be done a set way.