I think HRT effects you by making you like a horny teenager again. I suppose there will be many factors (such as if you were subconciously supressing a side to your orientation before) that could effect your sexuality. I do think a lot of it is down to that 'horny feeling' making you much more open to things then you were before.
I know for me when I first have my shot I am attracted to practically everything in some way or another
. I am usually very picky about women but that first week after my shot its like a free for all party.
As of yet I have never been attracted to a guy
but I do have far more gay fantasys since starting T and like I said, most of those occur in that week after my shot.
On a whole though since pre-t my fantasy's and preferences in women have expanded quite a bit. I suppose depending on how gay/straight/bi you are to begin with the hormones could effect you enough to expand who you like too.
Just my little theory
