Personally, I strongly believe that a society's sexual norms (standards of sexual conduct) are linked to religious beliefs. However, social and environmental conditions are secondary factors, which may also contribute to one's sexual orientation. For example, in prison, boarding schools, military and others, but they are not the actual or real determinants of one's sexuality. Due to peoples lustful desires, they cannot wait until the situation to be normal in order for them to be in an accepted sexual relationship. On top of that, rationality shapes morality and it has a lot of bearing on human behaviour. I do not believe that there is a society that can exist without religion and I have never heard of any. If we all agree that religion is a source of morality, then lets appeal to religions to help appreciate and acknowledge human sexuality so that we reach a consensus on the issue of homosexuality.
Sexuality and reproduction are fundamental elements in human interaction and society worldwide. Furthermore, "sexual restrictions" is one of the universals of culture peculiar to all human societies. Accordingly, most religions have seen a need to address the question of a "proper" role for sexuality in human interactions.
