Is it normal that my stepdad is like this?

We'll it all started when my mother decided to up and marry a man when I was 16. Me and my other siblings never met him. My entire life up until then it's been nothing but us together. He came off as distant, sneaky, and just a strange person. In which I still don't know or understand after 4 years. I never minded him being that way. Now that I'm a adult I come over to speak to my mother and he gets upset with my mother for having me over. He tells her he doesn't want us over there. He trys to intimidate her with his aggressive body language and I watched him. He controls and gets mad at her for helping me . My mother doesn't understand it either she thinks he's jealous of me. Is he jealous of our family relationship? Does he hate us? Or am I overreacting?