That kind of behavior in the workplace among adults would almost certainly be considered sexual harassment, and with that take on it, it seems entirely appropriate to me that you ask for a meeting with the principal. There's a real possibility that the administration will need to talk to your daughter as a first-hand witness to describe specifically what is happening. But I'd still talk to the school first and point out that your daughter might experience even more harassment if she's suspected of calling foul. Ask them what they plan to do to prevent that from happening.
If there are other students, or the parents thereof, who could support you in your complaint, it would probably be helpful if they stepped forward with you.
Yes, society as a whole is part of the problem. Sexy messages portrayed constantly in the media, kids with unprecedented access to media, parents who ignore, laugh at, or even encourage suggestive behavior, and on and on.
On the other hand, too much "prissiness" creates its own set of problems. There is a certain wisdom in keeping one's thoughts private, because verbally judging others for behavior they've accepted as normal can be puzzling at best, polarizing and provocative at worst. Social pressures are probably at their most intense during the teen years, and kids dread being ostracized or singled out as weird. Isn't life an interesting balancing act?
