I'm sure there is NOTHING at all that one can discuss with students that isn't offensive! My goodness, we are SO constrained and discriminated against because we can't talk about stem cell research to children! It's the Crusades all over again!
In your previous post to me you were applying a princible that said any subject was off limits if it was divisive to any parent willing to complain. Thus, under your system of justice, a bus driver better keep his trap shut about everything.