The American Indians had the concept of the berdashe or two-spirit people. A number of other groups around the world have roles for these people too (usually the men).
These men were quite feminine and could not cut it with the various boyhood rituals designed to turn you into a man. They decided to wear women’s clothes. They stayed home with the women and did women’s chores while the men went off in the day and did whatever. I believe that was permissible for a straight man to have sex with either a female, or if he chooses, a two-spirit man. The rest just saw sex with a two-spirit man as the same thing as sex with a woman.
There were also women who were quite masculine and not cut out for women’s work. They wore men’s clothes from early on and would go out and hunt with the men. They were considered “one of the boys.” I believe that she could hook up with another two-spirit woman and become a couple.
The transsexuals have tried to take over this discussion by saying that the two-spirit people were transsexuals. This is not so. They were merely homosexuals like the gay men and lesbians in our society.
On the other hand, there are tribes where there are no homosexuals whatsoever, and they don’t even understand the concept itself. They just found a Pygmy or Negrito group in a jungle somewhere who not only had no homosexuality but even lacked the very concept of it. It was literally unthinkable. They have also found some Amazonian tribes who have neither homosexuality nor the very concept of it.
One wonders if homosexuality is really an innate and immutable characteristic of human societies.