interesting loophole - goes to show the more you try to tighten it up, the worse it gets.
from Transgender Law Center (http://transgenderlawcenter.org/publications.html#family)
Transgender Family Law Facts:
A fact sheet for transgender spouses, partners, parents, and youth
Marriage1
Since, at the time of publication, California only allows "opposite sex" couples to get married,
gender matters. Because, as a transgender person, you may be unsure of what your "legal"
gender is, determining to whom you can stay married or get married to can be confusing. In
general, people are concerned about marriages that are either pre-transition or post-transition.
a) Pre-Transition Marriage (does transition end a marriage?)
When a couple gets married, and at some later point one spouse transitions, the key question is whether the couple, who are now same-sex, are still married. While neither the courts nor the legislature has yet said anything about these marriages, California marriage law generally says that a valid marriage can only be ended through death or divorce. Because of this,
it is our strong belief that pre-transition marriages remain valid after transition.b) Post-Transition Marriages (can someone marry based on their gender identity?)
California expressly recognizes a person's gender identity as his or her gender in some situations changing your gender marker on your driver's license or birth certificate, for example). For that reason, we strongly believe that you can marry based on your gender identity. The best way to support that marriage is through getting a court order and/or a new birth certificate that recognizes your change of gender.
However, even without such proof, you can still make a case for getting married. To provide you and your family as much protection as possible, we recommend that you take a
couple of extra steps beyond getting a marriage license. These steps include, entering into a
memorandum of understanding (MOU) prior to marriage, creating a will or trust, entering into a parent MOU prior to the birth of any children, and completing basic paperwork for power-of-attorney.