You didn’t previously assign Junior a menial and unpleasant task did you? At least he didn’t throw or dump a bucket of oily tools on your head… It can be difficult when you work with your boss’s son or daughter. A very cunning person with a good boss would use that as an opportunity to let boss see what a good worker you are. Remember anything you tell Junior or what he sees may get back to your boss. A foolish person might take Junior as a rival in the workplace and end up hurting themselves. The safest approach is to always be professional in your job AND remember Junior is potentially another set of ears and eyes for your boss. If Junior is impossible to work with you may need to look elsewhere but don’t quit until you find another acceptable job.

Good thing with all the employers clamoring for workers you can get another job easy enough.

….that’s what training is. Of course he has to watch you and correct you.