Boyfriend probs

Hey guys so recently I've been with my ex and we're dating again. The hisotry is my parents hate him bc we snuck around before and my mom thought he was pressuring me into stuff I didn't wanna do (he wasn't !!) and bc they found out that he smokes weed. And this ended us before. We started talking again and neither of our parents know. Im torn now though because I want to be honest with my parents but I know they'll ground and will try to ruin us again and most likely succeed...should I tell my parents what's going on?? Or should I ask his parents to talk to mine ?