According to Christianity: They are related in that they're both sin. Wrong in the eyes of God.
As for you, please don't insult my beliefs. If you want me to listen to your arguments you must be kind.
Actually, as a Christian myself, I find your beliefs to be a little too by-the-book for my tastes. I've come to believe that the Bible is open to interpretation, and I openly detest things that I find to be wrong, e.g. slavery. It is my belief that God gave us free will so we can use it. Also, while I'm here, I want to say something: I don't give a !@#$% what your belief is, don't act as if you're higher than someone else who believes the opposite of what you do. That's called respect.
Anyway, I only know one bisexual person, and that person is my younger sister, and I don't know any gay people. (Shock and awe, someone who doesn't know a gay person on the internet!) Do I think that either orientation is morally wrong? No, I don't. However, I do agree with the notion that homosexuality is indeed unnatural. Humans are, whether you like it or not, animals, so one of our most important instincts is reproduction. You know how young couples feel like they're ready to have a baby? That's actually instinctual. Now, in order to reproduce, you need a male and a female that are either hetero- or bisexual. This ensures that the two are attracted to one another. Lesbians and Gays are not attracted to members of the opposite sex, and thusly, do not procreate, thus making it unnatural as it does not further the development of our species.
Also, I believe it is a choice, and I will uphold that belief until I get solid evidence that it is genetic. And when I say "solid evidence," I mean more than stupid !@#$% like "science says so lol." I want cited sources, all organized by name and/or length.