My boyfriend just blew up at my son for the first time

My sons attitude has been horrible lately and it’s definitely been testing mine and his step dads limits. Well I’ve been with my bf for 6 years now since my son was 2. My son is now 8 and tonight we witnessed my bf losing it on my son for the first time ever. It was terrifying, our dog was cowering in the corner crying, my son was screaming and crying in fear and my one year old daughter was in hysterics. I’m still shaking. I’ve never witnessed this from him before and now This one instance has me afraid of him. It scared me so bad that I want to leave him. I hope it never happens again. I’m trying to hold it together for my kids sake but I really just want to curl up in a corner and cry. Up until today my bf has never even gotten angry in front of me. He’s usually super calm and laid back.

*Update* for anyone asking what happened my son wouldn’t eat his dinner, he was getting mad and slamming the table towards my bf and then crushing his food in his hands. My bf got angry and walked over to my son and started yelling really loud in his face, he yelled at him to wash his plate and go to bed. My son immediately started crying and then wouldn’t wash the plate so my bf yelled in his face again and then grabbed him by the wrists and walked him to his bedroom and told him to go to bed. My sons behaviour has been bad lately but my approach would not be to scare him. My poor kid told me he’s never coming out of his bedroom again. And I’m afraid of my bf now. That was so uncalled for and not okay at all. Please tell me if I’m wrong for thinking that was not okay. Sure I’ve raised my voice at my son but I’ve never walked up to him and shouted in his face. He’s only 8 😔