I think you can't say that gayness is natural or it comes from nature lol. If you want to test if anything is natural or not, then you have to study the nature and those things which are close to nature. Nature is pure, so you got to study pure things. Human beings are not pure at all, we tend to vary after each new generation, and our believes, moral values, ethics, everythings tends to change.
Study other living beings instead of humans, they are more close to nature than human being is. They are still doing the same which their parents were doing thousands of years ago. they haven't changed at all. so they are way lot more natural then humans are.. Study any living being except humans, and you will find that this gayness stuff isn't any where.. Even the animals who have no sense of anything don't do this gayness stuff. This shows that again this Gayness etc is **** created by humans. I am ashamed to say that humans are perhaps worst living being on this planet and we have no limits at all. we have proven in our history that we can cross every imaginable limit.