My mom touches me when I don’t want her to

I like giving hugs and kisses to my family but I don’t like being touched certain certain places. Nobody assaulted me so I don’t know why, but I just don’t like it. Today I gave my mom a hug and she said something about my clothes. She touched my shirt, but her hand was kind of on my butt so I just moved her hand. She grabbed my arm and said “I’m sick of you doing that. I’m your mom I can touch you wherever I want. I’m not violating you. Stop that or you’re gonna get it.” If she would have ASKED me why I keep on moving her hand there wouldn’t be an issue, but no. I’ll admit I could have told her I don’t like being touched in certain places prior to this and there wouldn’t be a problem. I have a hard time opening up and admitting stuff like that. I’m working on it. What I needed was for her to not assume I was trying to de disrespectful and ask me why I did that. I would have felt better and maybe told her. I think I’m mainly in the wrong though. I didn’t violently shove her hand, but I did take her hand off of me. I should have moved away.