Why is it ok to be naked on prom night?

I notice that it is acceptable for young women to show alot of skin when going to prom? I've never been one to have a problem seeing woman skin but I just wonder why is that? Is it protocol to where lingerae type dresses when going to prom? A pervert would enjoy a job catering proms or servicing proms in some fashion. Proms are sleezzier than night clubs.