My wife....kind of knew already, like before me. I can remember several times when she said "your such a girl" to me, over one thing or another. She finally dragged it out of me about 3-4 months ago. Your significant other probably already knows.
As to the holiday, my therapist agrees that it is a bad time to talk about it, but agrees that some family members will already know, and be okay with it. I plan to talk to my sister, who is the most open minded of my family, first. Everyone else later in the year.