There are bullies everywhere, even on here and bullying isn't always blatant and obvious, it can be insidious and passed off as a joke even, but it should be judged on how its perceived and if someone makes it clear its unwanted behaviour then those in authority eg teachers or mentors have a duty to deal with it and take it seriously even if they themselves may not get why certain actions or words make someone feel uncomfortable or negative. I detest when people have their feelings negated because the person meant to deal with it can't comprehend. Quite often the person dishing the treatment out may not realise how they affect others but if they are made aware and still continue that is when it really becomes a problem.
I'm sure I'll be disagreed with on this. Which in itself proves ny point kinda