Another authority figure that mades for sexy cosplay is the sexy teacher. I think that comes from childhood fantasies that we never got over, dreaming about making out with the teacher when we should have been studying during those years when teen hormones start to surge. It works for boys or girls and whether you play for one team or the other (or both!). I think the Japanese do a lot of the sexy teacher cosplay because I see a lot of it posted, although much of it quickly leads to teachers and students both being out of uniform.