If there was never a notice posted, mailed, or personally served, then I'm not sure how you know that there is a UD action pending. However, notice is a requirement. I suggest you see a landlord/tenant attorney who can advise you accordingly. There are many in the area who will give you a free or low cost initial consultation.
I am not sure what your sexual orientation has to do with it. Apparently, your landlord believes you have not paid rent and is now trying to evict you. If you did not pay rent when it was due, your being gay will probably not be a good defense.
Contact a local landlord tenant attorney for help.
A demurrer is not appropriate. A demurrer says, "Even if everything you say is true, you have no cause of action. " You need to oppose the UD based upon lack of service.
I am an Attorney-at-Law, licensed to practice law only in the state of California. Unless we have both signed a formal retainer agreement, you are not my client, and my discussion of issues does not constitute legal advice. Opinions expressed herein are those of the author, and do not necessarily represent the opinions of those who hold other opinions.