IMHO, the topic of tznius really should not be discussed between folks of the opposite gender that are not close family (although at times, the CR sure seems like one!)But if it come down to it, I’m a little more at ease in discussing tznuis issues with another woman, as it really is a public domain issue. once its outdoors, its public. Perhaps not the most rightous discussion for me to be having, but that’s life in the 21st century
However, if you equate avodah zara (see, no probelm with that) and the topic you mentoined (no, I still won’t spell it out) than either I’ve been in BP too long, or you’ve beenin NNJ too long.
Either way, to get back on topic, the real reason we seem to go off the deep end on issues like this is because its less about halachah and more about personal choice in how to apply halachah. And once it gets personal, it gets heated.