So human/animal coupling is a
huge theme in lots of mythology! One major example is the wife of King Minos, who coupled with a bull and gave birth to the Minotaur. Other examples I can immediately think of include animal brides (touched on
here), the various exploits of Zeus, and other myths related to shapeshifting. In terms of historical information, a lot of classical authors accuse the Egyptians of bestiality, but, much like today's jokes against the Welsh (or Scottish, Kiwis, etc.) it was likely just an insult. I did find some references indicating that some tribes indigenous to North America seem to not have had a taboo against zoosexual behavior, but I want to do more research into that. And obviously, religion managed to get its hands on this, as it has so many other things. Abrahamic religions have proscriptions against it, in Leviticus 18 and 20, although in the New Testament, some scholars have debated if there remains a proscription against zoosexual acts, based on Jesus' overturning of Judaic law.
I'll let y'all know if I learn more as I do more research.
