Consider the following two claims that some people seem to accept:
- Same-sex and opposite-sex sexual relationships are on par.
- Heterosexuality, homosexuality and bisexuality are on par, and persons of one orientation do not have reason to try to change to another.
I will argue that (1) and (2) are in tension.
Suppose that George is sexually attracted to people, male or female, of a particular ethnicity, and not at all towards anybody, male or female, of any other ethnicity. We would think this weird and maybe just a little perverted even if we accepted (1) and (2). After all, why should George limit his romantic options to members of a particular ethnicity? Indeed, his attitude would border on racism. Granted, if George hadn't done anything to choose his pattern of sexual attraction, and couldn't overcome it, we would not morally criticize George for his limiting his sexual interest to that ethnicity. But there would still seem to be something wrong with George.
I am not talking here of a mere preference. Perhaps there is nothing wrong with an Elbonian preferring Elbonians. But to be unable to be sexually interested in anybody but Elbonians is limiting, unfortunate, not quite right. And it is particularly odd if one isn't Elbonian oneself. It is certainly sub-optimal, given that sexual relationships with Elbonians are on par with sexual relationships with non-Elbonians, and it is not a good idea to have artificial limits in the difficult task of finding a suitable romantic partner. Furthermore, if George were not in a relationship, and there were a pill that had no side-effects and could remove the limitation, it would be reasonable for George to take the pill, at least assuming (1).
But the heterosexual or homosexual is in a similar state to George. The heterosexual man and homosexual woman is limited in sexual attraction to to women. The homosexual man and heterosexual woman is limited in sexual attraction to men. If same-sex and opposite-sex sexual relationships are on par (as per (1)), then there is something sub-optimal in value here—an odd limiting of possible partners on the basis of a quality, maleness or femaleness, that is basically irrelevant to sexual relationships according to (1). So, if (1) holds, then there is something not quite right with homosexuality and with homosexuality—it is a limiting of the relational options. Moreover, there would be reason to change one's orientation to bisexuality if one could do so easily and with no side-effects, thereby removing that restriction.
Thus, if (1) holds, bisexuality has a privileged status among sexual orientations, and, in particular, (2) is false.
One can, of course, contrapose the argument—and I think one should. If bisexuality does not have a privileged status among sexual orientations, then (1) is false.