Apparently, Rav Aviner has come out with some exceptionally stringent (link) rules for strict separation between the sexes amongst the faculties of schools in National-Religious schools system.
Thankfully, Rav Yigal Ariel (link) has come out with a response which is so imbued with simple common sense, it is a pleasure to read. (And an unfortunate comment on the state of the times when we have to praise simple moderate common sense!)
He complains that Rav Aviner has simply adopted a Haredi standard. Moreover he suggests that amongst the faculties of schools in the Dati-Leumi camp, problems of flirting and harassment are basically non-existent.
But I loved this paragraph:
בציבור החרדי השתרשה נורמה חדשה לפיה קובעים כללים חדשים, מחוץ להלכה, ומטילים אותם באופן גורף על כל הציבור. בכל הדורות נזקק האדם הדתי לרבנים כדי ללמוד את ההלכה ולהכריע בשאלות מסופקות, אבל בתחום האפור סמכו הכל על כך שיש לו ראש ישר, והוא בדרכיו שלו יתאים את המציאות בכל מקום לרוח ההלכה.
"In the Haredi community, a norm has taken root of new rules and standards, beyond the lines of "Halakha" and these rules are imposed on the entire community. Throughout the generations, religious people had Rabbis with whom they would consult in questionable circumstances, however in certain grey areas, they relied upon the fact that people had common sense and that straight thinking would apply the given situation to the spirit of Halakha."
I remember talking to Rav Lichtenstein some years ago about co-ed situations (in connection to Bnei Akiva.) He told me a story about his mother z"l . She frequently visited a certain European city and stayed with a particular family with whom she was friendly. However one Shabbat, there was a conference of the Moetzet Gedolei HaTorah in the city and many of the European Torah leaders were hosted by families. When she asked to stay at her friends, they informed here that they were hosting a certain Hassidish Rebbe and that he didn't have women present at the Shabbat table. If this bothered her, they suggested that she might prefer to stay elsewhere. And so, she stayed with a different family, a home where the Rogatchover was eating. He did have women at the Shabbat table, and that was fine.
Rav Lichtenstein was telling me that there have always been differing traditions in this context and we should not imagine that one approach or another is more "correct."