It may no be as far back or buried as deeply as a lot of people think. The orgy was a sacred rite. And perhaps practiced in religions it is not commonly associated with now. A symbolic return to "The Garden". You could look at it as shared innocence. Are you most vulnerable at your most intimate with the person(s) you adore? From some perspectives you are always making love with God AS God. Read your Sufi poetry.
Ben N. Moore
It's great to have here to be.