1. For the new guy, from now on, Don't teach him anything. If he asks you something and if it is your job to tell him, try to do that in front of boss or CC boss in email. Most importantly, you need to use a "mentoring" tone when you talk or write, to make people realize you are teaching this guy.
2. Don't discuss anything with him unless really necessary. You need to understand, an evil mind person is always evil mind. Don't expect him to change to be a nice guy.
3. For your boss. Be professional, if you know he is that type mean, don't make extra request unless really necessary, and don't ask for favor unncessary you have no choice. Meanwhile, don't be shy to say no to his unreseanale request.
Bottom line is , be yourself and if things really make you upset, get the hell out of that junk place and find a new job.