I can assure you that my instinct is to be with another man. I wouldn't be gay otherwise. What is your instinct is not necessarily mine, but the very fact I am this way, naturally, the same as millions of other people, defines it as part of human nature. It may not be the majority case but there's nothing inherently wrong with that. We are all minorities by some measure or another, whether it be hair colour, eye colour, height, weight, skin colour, sexuality or whatever else.
Society's attempt to repress homosexuality is just a typical fear-based response. Society doesn't understand and the hatemongers in it capitalise on this by stirring up nonsensical crap to give them power.
Attitudes towards homosexuality have changed hugely over time and in different ways in different parts of the world. It has flipped from extreme repression to the expectation that all males engage in homosexuality. What is 'normal' by a short-sighted definition has changed despite us as humans, biologically, remaining virtually the same. Does that not make you think "it's all in our minds"?