The reason that this particular honesty has not paid off is due to a full relationship's worth of lies and hiding. Honesty is the best policy. When I met my wife I said I wanted to wear panties (as that was as far as i had realised at the time). When I wanted to start wearing women's clothes, I told her that day - no problem. When I discovered my need to transition, I told her, that same day. She's been with me all the way, and will be. I recently told her I will need to go further in transitioning; again, fully accepted. Why? Apart from her amazing beingness, it is because there was no lie, ever.
Starting a relationship knowing about one's proclivities, and hoping that love and time together will mean she does not want to split once the truth comes out; well, that is the foolish plan. Just. don't lie.
