Skimming through the papers I sometimes come across little nuggets that suggest that script writers are not actually making it all up:

In 1974 Hargis had conducted a wedding for two of his students. On
their wedding night, in an episode reminiscent of the scene in Cabaret
when Sally Bowles and Brian Roberts admit to having had affairs with
the bisexual Max, the bride and groom confessed to each other that
neither was a virgin and discovered that Hargis had deflowered them
both.

Cabaret was written well before 1974 but I’m not all that sure about Rocky Horror. The question for me is who is copying who? Hargis the book and the movies? Or they him? Or is it all an echo of some more basic story back in the collective unconscious?