>>I don’t know why a triangle would suggest anything sexual. Usually, it is symbolic of ambition and energy (fire). It is male but if there is esoteric quality to it — perhaps derived from the Egyptians or Greeks, maybe Masonic in nature — that points to sex, I don’t see it. <<
I’m guessing it’s hard to pick a truly original symbol for anything.
I would also guess that they wanted to pick a symbol that would look perfectly innocuous to anyone who doesn't know what it means.