HOMOSEXUALITY has been stigmatized for century upon century, and in many cultures across the world and through time, mostly seeking to stigmatize relationships between members of the same sex. Almost invariably, when it is criminalized, those who criminalize it (or would do so) refer to it as the "crime against nature" or the "sin against nature." The presumption is that homosexual behavior is a perversion, and a uniquely human perversion, engaged in as the result of what is presumed to be a learned attraction to members of the same sex.
There's only one problem with that assumption: None of it is true.
There's clearly a wide range of homosexual behaviors in the animal kingdom. It's widespread, common and impossible to deny or explain away any longer. Homosexuality is natural as green grass in summer, and it's high time we accepted that fact.
The birds do it. It's been described in 130 species of birds. The southeastern blueberry bees do it. Same sex pairs of animals kiss and caress each other with obvious affection and tenderness. Male pairs and female pairs form long-lasting pair-bonds and reject, threaten, even fight off potential opposite sex partners when they are presented with them. Same sex partners engage in almost every conceivable means of sexual expression throughout the animal kingdom.