OK I have been trying to reference this anywhere.
What is this "centipedes in the vagina" expression and where did it come from?
Seriously, damned if I know!!
It cropped up on this board sometime ago and it makes absolutely NO fucking sense to me. I'm as much in the dark as you are!! And I can't say as the link that Callaway provided made it any clearer.
A few guesses from my perspective, it either refers to a peculiar sensation women feel in regard to periods,, sexual sensations or the discomfort from one helluva yeast infection or STD.
Somethings I hear............well, I don't want to know!