I've met four people (so far) that are neither male nor female, or perhaps actually both. Their chromosomes were neither XX nor XY, and their body parts were fairly random combinations of male and female, yet still "fully operational". After doing some research, I understand there are at least 23 distinct sexes for human beings.
So ... if a hermaphrodite marries a woman, is that a same-sex marriage? What if they marry a male? What if they marry both, but carry the child of only one?
Thousands of people with their own idea of gender are awaiting your reply. Your judgement is final, because you have the authority to ostracize and hurt any human being you want.
PS -- The following website is very well-done, and our legal system might consider this option as well.
http://www.malepregnancy.com