Estrogen and heterosexuality?!

I've been busy studying for my finals, which I had two of today and one on Friday. Whilst studying for physiology I came across some information that I thought very interesting. It is common knowledge that there have been and still are many people out there who think that homosexuals are unnatural and that think it's BS that they don't choose to be the way they are. Now, I found something interesting in my physiology book, and I quote, "Estrogen receptors have been identified in the testes, prostate, bone, and elsewhere in males. Recent findings suggest that estrogen plays an essential role in male reproductive health; for example, it is important in spermatogenesis and surprisingly contributes to male heterosexuality" (Human Physiology 6th edition, Lauralee Sherwood). This is just a bit of what estrogen does in the male system, but I find it interesting that there is physical evidence that homosexuality isn't necessarily a choice. I don't know, maybe there are some people that choose it, one can't rule out the possibility, but I think that this is a very interesting point. Of course I think it's cruel and unchristian (that's important to mention because so many of the people who discriminate call themselves Christian) to discriminate against anyone for any difference they may see in someone else; who are these people to say whether God loves someone or not? Doesn't God love everyone? I think he does. Anyway, I just had to put that bit of information out there. :) Other than that, studying is going good, but I can't wait to be done on Friday!