Should I be nervous about introducing him to my mother ?

I'm 18 and he is 21 this weekend my mom and him are going to meet and I'm scared as shit she made it clear if she doesn't like him he has to go and me and my mother don't get along I'm just trying to be respectful but I'm scared she is not going to like him and he is going to be thrown off by her and the way she might come at him I'm trying to prepare him but you can't really prepare for the unexpected I really honestly don't want them to meet anymore