My brother forces his girlfriend

Date: 8/10/2019

I was at a hockey game and decided to get front room seats since there were only three rows and the first row wasn’t even full. Then I was in my room and I heard my brother talking to his girlfriend. He argued with her that he was going to go in the shower with her. She didn’t want that tho but he was pressuring her and it made her uncomfortable. I came in think I whooped his ass?? I felt proud that I saved her from my brother. Then moments later he’s get aggressive towards me and starts talking aggressively. I was scared he was stronger than me. But then my mom and sister came so he couldn’t hurt me. Someone showed me something and I told my brother ‘yeah you should kill me or ...’ I said other things and he agreed with me. Then he started telling my his ideas to kill me and I regret putting the idea in his head. I was terrified.