I understand that other people are saying 'you can't help what you're sexually attracted to'; and maybe I'm too much of a pusher, but I've found that almost everyone I've met is at least a little queer once they're honest with themselves. (Uh ohs, am I being controversial? Well, we're ->-bleeped-<-s! Hate it if you need to, but to the rest of the world, our very existence is controversial!)
I mean, if you think about it. We're female men. Many of us eventually become hormonally male with testosterone, or even get something like phalloplasty/top surgery and are able to have our gender marker changed on our papers- but in the end we're still XX chromosome, female from birth. This puts us into a bind because, who are we supposed to date without needing to be 'accepted'? I mean really, think about it.
Being with a straight girl is problematic because we're female, two females together is seen as 'gay', even if one is actually a man, so she'll have issues with your genetics 'making her gay'- loss of attraction because you're female. Gay men have the potential to be an issue because we're not 'real' 'cisgendered' men- we 'used to be women', which gives gay men issues, loss of attraction because we're female. Being with a lesbian is an issue, because even if we're female bodied, we're men, and lesbians are, typically, attracted to women, not men, loss of attraction due to masculine gender identity. Straight guys are an issue because even if they are along for the 'female' ride, they have issues with the relationship 'making them gay' when they come to the realization that you 'are actually a man', loss of attraction due to gender identity. So there are problems with straight women, gay women, straight men, and gay men. That pretty much rules out everyone who isn't already bisexual, pansexual or just already heavily queer-and-otherness-identified, unless they're open to doing some soulsearching and interpreting the guidelines of their own sexuality.
So there's pretty much going to be some kind of roadblock no matter what. I've had a lot of issues with 'previously straight' types- the thing is, a look at what testosterone does to the body points out some of the similarities between females and males; if you're on T for a while, your 'clit' gets bigger, it grows into a 'little dick'. The thing is, really, it's always been 'a little dick'. That nubbin of erectile tissue between your legs is what your boyfriend's penis started as, in the womb. If he licks on that, what's the difference between it being the size of an m&m and the size of a jawbreaker? It's made of the same thing, made of the same person. And even if you've only recently come out as trans, haven't you been a 'man inside' this entire time, anyway?
That's part of my issue with things like this. You're not going into a cocoon and magically transforming 'into a man'. You are a man, and have been a man(I'm assuming), just not in a physically visible way so as to let the world easily know. So whoever you're with has been dating that person, a man, for however many months already. Does this 'turn him bi'? Does sexual orientation really matter? As transsexuals, many of us are forced into a state of in-between-ness and otherness for the rest of our lives, which means that we're at odds with any clean-cut road of sexual orientation.
Using myself as an example: how can a straight girl, a lesbian woman, a gay guy, and a straight man all date the same human being? I've been in relationships with each of these labels of sexual orientation. I've been the same person each time, I haven't been going back and forth. I'm a transsexual man, a female man, I've always been. I didn't 'make' anyone gay or straight, but I've 'made' people actually think about their sexuality for more than a few seconds, and the results aren't always 'horrible'- and face it, there will always be 'soul searching', if it isn't with the guy you love right now and want to live with, it's going to be with some other person. It's never going to be easy. But if you've always been a man, how is your bond magically broken by telling him?