All thought and behavior, including homosexuality, is regulated by the physical structure of the brain. The physical structure of the brain is founded in genetics and altered by its environment through development and experience. We alter our brain every time we experience anything. It seems reasonable that any alteration, either through inheritence, development or experience, might lead to homosexual preferences, so it is likely not an either/or question with regards to nature or nurture. I suspect, in the case of my cousin, that being raped by a male at the age of two might have contributed to lesbianism. I can't prove it, but if one develops a primal fear of the opposite sex, then the natural sex drive combined with an aversion to the opposite sex, might naturally result in an attraction to the same sex. However, many homosexuals do not report ever having such a pivotal moment, but just a natural awareness from the earliest time they can remember, suggesting that inheritence may be in play for others.
Why do some people like chocolate? A gene that alters our sense of taste? A pleasant memory associated with consuming chocolate? An unpleasant experience resulting in an aversion to vanilla with chocolate being the obvious alternative? A personality that is inclined to conform with a social expectation of preferring vanilla, or a contrarian personality that seeks to express itself through chocolate? There are a lot of different paths that one might take to arrive at their destination. It's an interesting question, why are we who we are, but merely academic. An indescribably complex interaction of nature and nurture makes each of us unique. Asking nature or nurture suggests a false premise that one can exist independently of the other.
Asking if God made it so is simply a failed attampt at ducking the question, because even if there was a God, if that God created nature and nurture, then you have only arrived back at the same question of nature or nurture again.
So, nature or nurture? The answer is 'yes'.
