this is just a thought, they could be our sister...
Ok picture a woman, she is really beautiful and dress modestly and than imagine her without a flesh (without a body) and she has no image now just her flithy feces soul that needed to be clean and has to be purified is left. then imagine her trying to make sins with you... would you do it? (of course not because she doesn't have a body but imagine it into a physicallity without body) or would you be scared and run away... that's how we should picture immorality in these days trying to make us sin or when we are falling by watching pornograghy which we shouldn't...
Bascially we have to picture them in the inside instead of the outside and have to remember we could have been reincarnted to a women also in pervious life or might be a woman next life time, we don't know and Only G-d knows and He can do anything.