As a heterosexual and a MTF transgender who did the whole marriage thing, (no kids) I can tell you many of us struggle to accept the fact we are transgender and do things like get married,join the military (which I also did) and other things to block, deny the transgender urges... in most cases it doesn't work and we are forced to choose to live our lives constantly fighting the feeling to want to be the opposite gender of our birth or accepting the fact that this is part of who we are and letting ourselves express it, for some it only leads to crossdressing, for others, true transsexuals like me it leads to the road to transition to female completely. Acceptance was the hardest part for me, I always have had these feelings and always knew I should have been born female but I fought it for so long it caused depression anxiety etc. Now that I am on the right path I am no longer depressed anxious or self-loathing, no longer need anti-depressants.

If you really want to read more about transgender and sexual orientation there is a great book called "When the Opposite sex isn't" see my source below. Sexual orientation has nothing to do with being transgendered.

I'm a bisexual transman.... your question is flawed.

That's like asking how a straight boy would think he's a lesbian transwoman. He wouldn't. He'd know he's a dude.

My attraction to other men has no bearing on who I am as a person. Gay, straight, or bisexual, I'd still be a man because that is the way my brain was wired.

The gay man would realize that he doesn't like being treated like a girl. He would be annoyed by all his boyfriends treating him like he's feminine. He would probably want to engage in sexual activities that his straight male partners don't want, and wouldn't want to engage in sexual activities that his straight male partners do want. He probably hates his female body too. It's kind of hard not to notice that.

Same thing with the lesbian woman.

By the way, when referring to transsexuals, always refer to them by their gender identity. Thus, the FTM is a transsexual man and uses male pronouns and probably doesn't use the name "Elizabeth"; the MTF is a transsexual woman and uses female pronouns.

"I am aware that gender and sexuality are two completely different things."

"even heterosexual transsexuals become unsure of their gender identity and some MtF end up marrying females and having children while in their male body"

You might be aware that gender identity and sexual orientation are different but you clearly don't understand how. Otherwise you'd realize that the second partial quote makes no sense.

Sexual orientation is about who you're attracted to.

Gender identity is about your sense of self in terms of gender.

Who you're attracted to has no impact on your gender. We're not trans because of who we're attracted to we're trans because our brains don't match up with the body we have.

In short regardless of what I identifiy as it wouldn't change that I'm attracted to men. In the same way it that regardless of who I'm attracted to it wouldn't change that I'm female.

Transgenderism isn't a choice.

What is between your legs doesn't mean that's your gender, it's what your brain tells you.

I agree with leah, I can't add any thing to her answer

Freaky-deeky without a clear active choice.