I have asked a question on how to Earn your kid's trust and getting them to confide in you and "complain" about getting bullied
The question is
How not to lose the trust now that you earned it while also effectively protecting the kid from bullying?
You heard from the kid themselves or from a teacher or in any other way. What should you do? Visit the principal ask for explanations (maybe threaten litigation) ask to speak with the bully's parents and get the bully to explain themselves and publicly apologize? How vigorous and non-tolerant can you be so that you are effective in the long-term (you will not be able to protect the kid if you lose their trust)?