Boyfriends family drama

My boyfriends mother and little brother lives in a different state than us (16 hours driving). They can down to visit us and other family in the area for Christmas. On Christmas Eve, all of us went to my dads side of the family ( my uncles house) 8:30 pm -12:00. Everyone was tired especially my BF mom and little brother. My BF decided to drop them off at home because we still had to go to my dads house. When we got home and parked the car. They went straight to the door. I was grabbing presents we got at my uncles house and my BF was talking to me. When we got out the car, my BF mom was yelling at my BF to hurry up. My BF said something about this is his home. My BF mom said hurry the f**k up. I guess that got to my BF because then he said to her grab your shit and go. For a little I thought they were joking around. Immediately after my BF opened the door to the open, my BF mom started screaming, pushing, and hitting my BF. I was shock! My BF little brother was yelling stop and crying. I had to get in the middle because she cornered him and started punching him in the face. My BF never hit back. Then my BF said old what this family did to you to make act this way but you were never like this when you were with his ex name. Which made me feel a type a way. Its a mess right now. My BF doesnt really want to talk about. I can feel the tension. My BF mom is at his aunt house right when we were suppose to go yesterday to spend Christmas but he didnt want to see his mom. I feel helpless.