Is she your only cat? Was she a stray you took in? How old is the cat and is it fixed?

I hate to say it because I do like cats but I have to agree with your husband. As much as it's nice to have a cat, there's no way I'd want to live in a house that a pet is using for it's toilet. You may have to decide at some point whether it's right to keep an animal that is upsetting your spouse.