But answering to your question, develop a new sexual orientation i thoug is a mix of inner closet desires, whit some kind of chemistry in the brain changed whit the hormones.
The only way that you can avoid you biological sexual orientation (homosexual, bisexual or straight all are primary a biological issue i thoug) is trough...
a) a big trauma what dont let you enjoy and make you go whit a gender that you really don like...that happen to me in the past when i try whit men, i was so screwed inside that i let my masochist urges put me in a bed whit a man...a kind of autopunish for not be "enought man / man deserve ->-bleeped-<-" the idea in some way was a lot of erotic for me in my mind..but at the "true moment " was a horrify experience what make me sick...what sadly make more strong the surge auto destructive after ... :/
Actually i am lot more self confident and that urges are controlled and well i know a lot better my real tastes of genders.
b) social closet , a so much hard need to fit in a social role and a not so hard need to have sex

PD: i am a kind of narcissist and i cna find interesting be flirted by man...,sure i would enjoy a lot more the flirt of a woman (cisg or trans) but well...cisg woman dont used to "hit into men" they are more "pasive" and trans woman are very few 1 for every XXXX thousand cig woman...and well must admitt that i feel guilty if i dont give the same treatment to a trans than to a cig so i try to be more active whit them... So sadly i end again using sometimes men for my selfish needs xDDDDD