Some same sex couples still sue the traditional Husband and wife designation. Know a lesbian lady that always refers to her partner as her husband.If they are married, they are husband and husband or wife and wife. My married gay clients and friends refer to themselves with those terms.
For what it is worth, I've never liked the term "partner" in this context because it is too ambiguous. "Life partner" makes the relationship clear, but the term is out of vogue.