Did your boss ask you to train him to take over your current work so you can move up for a different level of work? Or just need you to demonstrate that you are ready to a senior level through training him and you will do the same work? To me, this would make difference on how to handle the situation.
In my opinion, I wouldn't really teach him much unless he respects me - this is my very bottom line. Just think about that you are currently sharing your knowledge with him and he is still new to the work but he doesn't seem respect you and appreciate your help already. How can you expect he would treat you nicer after he gains more knowledge from you and can handle his work independently? This is my first impression and concern after reading your post. Certainly, you need to handle this strategically based on your specific situation. Good luck!
