This is typical of the trend nowadays of suesuesue for the smallest things

Perhaps the teacher shouldn't be showing R-rated movies to 12 year olds, but then perhaps our society should be more open to this kind of thing? If it had been a woman-man sex scene there wouldn't be these problems.
I don't see the problem with showing the film, really, but the teacher should have expected this kind of backlash when showing an R-rated controversial film in the USA to children...