As a person with transgender experience, I find the terms "homo-" and "hetero-sexual" (and their colloquial equivalents - "gay" and "straight") to be problematic, because it is not clear whether they are referring to a person's physical sex or mental gender. And the cultural stereotype of the transsexual experience is a person born in the wrong body - whose gender doesn't match their sex, and who must embark on a journey to acquire conformity between their sex and gender. Which is ironically cis-sexist, because it presupposes that sex and gender must align in a stable individual. That, for example, a female-gendered person can't exist comfortably in a male body or vice-versa. Which has not been my experience.
Non-op transgendered individuals surely exist, but their experience is not part of the mainstream consciousness. And anyway, it complicates these terms - "gay" and "straight" - because without indicating whether they are referring strictly to physical sex or mental gender, they presuppose that the two are the same. Imagine that a woman born in a man's body identifies as female. Let's say she is attracted to men. Is she gay, or straight? In her mind, possessing the body she was meant to have - a female body - she would be straight. But let's say that while she still possesses the body of a man, she has a sexual experience with a man she is attracted to. Is the sex they have gay or straight? In the transwoman's mind, it may be straight, but to any outsider (as well as the man who is sexually engaging with a penis), it is a sexual experience between two individuals who each have a penis. How can that be anything other than gay? (I have to credit Liz Taylor from American Horror Story: Hotel for presenting me with this conundrum).
Granted, the transwoman's gender identity makes it more complicated than a straightforward cis-sexual experience - because the mind, and the gender identity of the participants, is an important aspect of a sexual experience. That's one reason why some people are specifically attracted to transgendered and transsexual individuals. You can be sexually oriented towards one sex and another gender. Some people may describe it as being attracted either to tomboys or girly men. In that case, what determines whether you describe a person's sexual orientation as gay or straight? Does it depend on the target of attraction's physical sex, or gender identity (or expression)? And is the answer to that question something that we would all be able to agree on, so that we can use consistent language? I would argue that these terms are simply not adequate to use in a trans-friendly framework - one that presupposes the possibility of a disparity between one's sex and gender.
I've created this graphic to illustrate my point. For the moment, we are ignoring the intersexed, in order to keep things relatively simple. On the left, we have what I call the "cis-framework", because it does not differentiate between sex and gender; they are presumed to be the same. As such, there are only males and females. A male/female pair is defined as being "straight", while a male/male pair is called "gay", and the female/female equivalent is termed "lesbian".
On the right, we have the "trans-framework", which differentiates between sex and gender. The symbol indicates physical sex, while the color refers to mental gender (we are assuming a binary gender, although the reality may be even more complicated than this). Thus, a blue male symbol refers to a cis-male (who identifies as the male gender), and a pink female symbol likewise refers to a cis-female. The previous pairings that are defined as being traditionally straight, gay, and lesbian are duplicated, this time with the matching genders filled in.
But now, you'll notice that we have the addition of transgendered individuals - a male symbol colored in as the female gender, and vice versa. These may be pre-op transsexuals in the midst of transitioning, so as to align their physical sex with their mental gender (and thus satisfy cis-sexual standards), or they could be non-op transgendered individuals who are comfortable having a sex and gender that do not match. Either way, when we start pairing them up with other individuals (whether cisgendered or transgendered), the terms "gay" and "straight" break down.
For example, try to define the pairings listed in the lower right corner. If two people who both identify as female have penis-in-vagina intercourse, is this gay or straight? What about two people who both identify as male? Is it still straight if the one with the penis identifies as female, and the one with the vagina identifies as male? What if they exclusively have anal sex with a strap-on, and never penis-in-vagina intercourse? Is that gay or straight? Is it any different if this same situation occurs between a cis-male and a cis-female? Is it gay if one member of a couple lives as a man, and the other as a woman, but they both have penises? Is it lesbian if they both have vaginas? Do they have to identify that way, even though doing so might "out" the transgendered partner who is trying to pass? Two men with vaginas could get by calling themselves gay, but are two women with penises allowed to identify as lesbian? Can you be "straight by day, but gay by night"? And if so, how does one differentiate this situation from that of a family man who secretly visits gay bars? Should the terms we use refer to romantic pairings or sex acts, since they cannot consistently be applied to both? Can two gay people have straight sex together, or vice versa?
I hope you see by now that when we include transgender individuals, our cis-sexual framework for sexual couplings falls apart. My solution to this problem would be to redefine our terminology for sexual orientation by referring only to who we are attracted to (e.g., man-attracted, woman-attracted), while indicating our own sex and gender separately. I call this SGO Notation (for sex, gender, orientation). But I'll have more to say about that in a future post.