A few months ago I followed a story wherein a teacher was suspended for showing her all-girl class (she supervised cheer-leading or somesuch) the results of her breast augmentation surgery done over the summer.
My views is that her actions were entirely appropriate; I'm sure teen-aged girls have an intense curiosity regarding the subject and would benefit from the project.
'Til this day I appreciate my 9th-grade "health" class (all boys) on disabling a brassiere latch. No telling how many accidental finger amputations were prevented by this timely instruction.