Is this work place harassment?

You have a few options. It doesn't sound like harassment to me, but it does sound like he is a jerk and is taking advantage of you. You are perfectly justified to stand up for yourself and tell him off. My advice would be to move to another department in the store or just quit if he is not doing as you ask or is making threats. If he's older, he's likely not about to change, so you are better off just getting away from him.