Interesting question. As it was explained to me, one obstacle to enacting Federal anti-discrimination legislation to protect gays is that the “protected class” (those who may appeal to the law for redress) so created is difficult to define in a concrete way – more so than African-Americans, Veterans, women, and so on. However, if the legal system does accept that homosexuality can be definitively “proved”, then the objection has no merit.
I agree with Ferret Herder: I doubt that “proof” of homosexuality would be an adequate defense to the accusation of rape, any more than “proof” of heterosexuality would help a man accused of pedophilic contact with young boys. Neither crime/act has much to do with sexual attraction or preference.
In fact, about 3-4 years ago, a case dealing with male-male sexual harassment reached the U.S. Supreme Court. The plaintiff, a presumably straight worker on an oil rig, claimed that he was subjected to sexual harassment by his presumably straight male co-workers. The behavior ascribed to the defendants would clearly have been considered “sexual harassment” if directed towards a woman; but the defense claimed that in this case the behavior was not sexual harassment because a heterosexual man is incapable of such behavior towards another man. The case was interesting to me because it questioned the underlying assumptions about sexuality in the law itself, and raised the issue of “proving” one’s sexuality – which the defendant was not required to do this.
IIRC, in the end the court decided that this did, in fact, constitute sexual harassment, because the acts were clearly sexual and a “reasonable person” would find them sexually offensive or objectionable. However, no decision or comment was made about how one proves sexual identity/orientation in the courtroom, probably because in this case – as in a case of rape – sexual self-identity is not actually relevant.
As for the military: yes, I do believe that a person is discharged immediately if s/he positively self-identifies as a homosexual, or is observed to engage in homosexual activity. There have been several cases like this since the “don’t ask, don’t tell” policy went into effect. But military law is distinct from civilian law.
As for domestic partnerships and employment/insurance benefits: each company (or state, or city) sets its own standards for assessing a domestic partnership. I think my company requires proof of a minimum live-in relationship of one year between same-sex partners, without regard to committment ceremonies and the like.
I suppose there isn’t anything which would prevent two straight men from pretending a domestic partnership to reap the benefits, just as an immigrant can establish a legal marriage with an American citizen to obtain a “green card”. But if the insurance company (or INS) decides to investigate, the couple had better make it look good! However, I doubt you would find too many straight men who would be willing to pretend they are homosexual, even to beat the system.
