To be fair, I have only skimmed read this thread. Now if I read this right, you love this job, so why should you resign. Surely this employer has policys covering all scenarios, and surely this includes one on bullying. I think you should report this person, first by speaking to the next immediate superior, know the policy so you can quote it if they try to sweep your complaint away. Sometimes these things actually need to be formalised before they will take any action. Gone are the days when people just pulled them aside and had a word to them, although I still will talk to someone about thier behaviour, if there is no resolution I then take it higher. Good luck, chin up. There have been some doozey responses here....................!!!