Small note regarding the "not natural" part of homosexual intercourse:
Ye know, it is actually quite hard to determine if it is natural or not. You see, for starters, homosexuality was always present in human history. Let me remind you that Julius Caesar was bisexual, for instance, and there are historical documents that confirm he had relationships with both men and women.
This applies, to a certain extent, to people like James Wolfe, Friedrich Von Steuben, amongst other important historical figures.
Now that's with humans. Let us go one step backwards in evolution: animals.
Truth be told, I am not interested in finding out more about this topic, simply because I find it most hilarious, yet quite unpleasant and disturbing. However, I did see two of my male dogs going at it... more than once.
Hopefully this makes it more clear:
Now, leaving the Bible aside, I define "natural" as something that is NOT artificial, ergo not created by humans. The fact that there is "animal homosexuality" proves under this definition that it is something natural, yet uncommon and not socially accepted.
Here, one must find the proper way to distinguish the terms "normal" and "natural". Many things can be normal, but not natural, such as eating genetically modified food, fighting wars, hell, even needing money to pay your life.
Others can be natural, but not normal, such as inactive volcanoes suddenly flooding an entire area on lava, earthquakes, people who end up extremely tall (Ex. 8-9 feet high) or short (Ex. Verne Troyer), etc.