Blueyed, I'm sorry your going through this confusing time. I want to say right off the bat that none of this is your fault, it's not about your figure or gaining a few pounds. Nobody gets gender identity disorder because their partner gains 15 lbs. It goes deep, to the core of one's identity. As confusing as this is for you, it's probably even more so for your fiance.

If he's a cross dresser and if you're non-judgmental, it's no big deal as long as you can work it out in an agreeable way. Most experts in human sexuality and gender consider cross dressing a harmless fetish.

If your partner is experiencing gender identity disorder or gender dysphoria it becomes a more serious problem for the direction of your relationship as a romantic couple. The two of you may transition to a different kind of relationship or you may decide the new realities are too much.

Participating in counseling as the two of you figure this out is important, especially if it can help you talk to each other in an open, honest and non-condemning way.

There are on-line blogs and support networks specifically for the spouses of cross dressers and transgender and transsexual people. I don't know which ones are the most helpful, but I'm sure there are other posters here who can offer guidance in that regard.

I wish you the best.