Unnatural ?

Homosexual behaviors occur across cultures and generations, in consistent proprtions, and as far back as we know. these include courtship, affection, sex, pair-bonding, and parenting. In some species 44% of the observed population would be characterized as homosexual. In humans the number seems to be closer to 10%. Homosexuality is an expected occurence in nature.

Moral Implications?
The clssifications of natural and unnatural say nothing about the morality of any given act. If nature provided the standard for morality, we might be in-breeding, keeping harems and devouring our young with impugnity. We might be shamed by unnatural acts such as driving a car, or talking on a telephone, or wearing clothing, or taking medicine, or countless other things that exist in human society alone and nowhere (else) in nature.