We are camping, my family just bought land to build a house on. I was in the camper trying to sleep. My dad bf and brother were getting ready to hog hunt. It was dark so I didn't see anything but heard my brother getting spanked. Step mom " this business of u falling down when u get spanked is done" they walk toward me and they r in front if the camper when she starts spanking him again. And the next thing you know my brother is screaming "my neck my neck". My dad comes and says to her "babe that's his neck" she says "I know. If he would listen then I wouldn't have to do this" he says "but his neck" and she let's go I guess and she says "we will talk later" and he says "yeah. If I did that to one of us kids how would u have reacted" and her and my brother get in the camper he's crying and asked her if he could go hunt she said "no ur brat" and he says "but I didn't do antthing " so she smack him in his face. I assuming hit him in the eye cause he said "my eye" and starts crying. She tells him to shut up but he says it hurts and she smacks him again.

What should I do. I am angry at my father for not getting my brother away from that and just going off to hunt. I turn 18 in 8 months. If I would have said anything who knows what would have happened...