Being still pretty new to HRT, my comments may not be entirely relevant to your question, but here goes.
I was always adamant to most others that I was a straight heterosexual male. I had bisexual tendencies though, but it had to be the right guy and under the right circumstances. People used to think I was just a closeted gay guy. I got married 8 years ago, we've been together like 11 years in total, and we just had our first (and probably only) baby girl a few days ago! Yay!
Since coming to terms with my transness though, I've embraced the idea of being bisexual a bit more, but with that in mind, I have virtually no libido now that I'm on HRT, lol. It still takes just that right, very specific guy to pique my interest, but girls are still my bread and butter. They may not get my motor running like they used to, but to me, the female form is the definition of sexy. Va va voom! And not only do I want to be with them, I want to be them, and it makes me so happy everday that I look in the mirror and see Kristina smiling back at me slightly from behind my boy-clothes, hehe.
Once I have GRS, I'm really looking forward to some good old fashioned P2V action though!