... Star Trek portrays humans in relationships which are basically beastiality (humans mating with other species)
Beastility is people having sex with animals, that where you get the "beast" in bestiality. Which of Trek's intelligent species do you believe to be "animals?"
... thus a society which accepts that ...
I never considered this before, but given how Vulcans feel about Humans and non-Vulcans in general, I wonder how they felt about Spock?
A contaminate in the Vulcan superiority?