I think that there is a possibility for people to be somewhat bi-sexual, since accidental erection, thoughts , or environmental events can occur to result in mixed up thoughts or feelings, but that does not mean that they are bi-sexual because people often choose a polar side because of their beliefs and preferred tendency toward one sex. On a side note, I've also heard that women have more tendency to be bisexual, so it looks like there is hope for those people who are massively turned on by that kind of stuff.
I think that homosexual traits in some people may be inherited, in which case it is not (at least at first) a matter of choice, but in some other people, they are not.
Is being gay a matter of right or wrong? I would say not really.
I'm not anti-gay, but I am not for me being gay, since it is totally disturbing for me to think of myself being gay. There have been times where I was afraid that I might be gay, and of course the fear results in disturbing thoughts, and I think that kinda is the fear of many straight people especially if they would have to doubt their own conclusion on their sexual orientation, and that cycle raises frustrations. The other thing that I believe is that, even if I do have some sort of gay tendency, I would choose not to be gay because of beliefs (not religious).