The split between the sacred and the sexual started when the patriarchy took over, and women needed to be controlled so that inheritance could go through men. Read "When God Was a Woman" by Merlin Stone if you'd like to know more. Before that, there were priestesses who used sexuality as part of their rites, but that practice had to be condemned if women were to begin to accept being owned and controlled by men. The most effective way to do that was through religion -- if you f**k someone else, then you're a whore and you'll go to hell! (The original meaning of "whore" was "healer".) So the motivation for making non-monogamous sex (for women, especially) immoral was originally financial, not moral.
When I was working, I used sexual energy as a tool for healing and for expansion of the spirit. It is a powerful force and when used with knowledge and skill, it can be a potent agent of healing, and for having a direct experience of enlightenment. Di you ever wonder why so many people say "Oh, god! Oh, god!" so much when they're coming?
I'm working towards a time when the sacred use of sexuality is reclaimed. It has been forgotten, but it is returning.
If you want to know more about how a prostitute can be sacred, then read my book!