It seems that one of the things the pagans liked to do in order to cement their allegiance to a god was to stand in line that proceeded up to the god and when they (men and women) would get in front of it they would lift up their clothing to reveal their naked private parts.
A concerned rabbi came up with the idea of the loin cloth to discourage the Jews from participating in the pagan practice.
Aha! I always wondered what goes on at the Hollywood Obama fundraisers.