<human>: Can you give me the gist of the text in a nutshell?

So allow me to set this up. It's late Sunday night and I'm in the process of cooking dinner for my gf and my self. I notice my phone going off and I go to see who is calling. Mistake number 1. It's my brother. I have two missed calls and a text urgently asking for a return call. My first thought is something is wrong with my grandfather. I call back. Mistake number 2. 

As the phone is answered I am hit with anger and threats towards our father. Physical threats are issued towards my dad and I begin to threaten brother losing my cool and calmness. I hang up the phone and my gf is trying to calm me down. At this point I am shaking with rage and I don't even know what is happening. I proceeded to call my dad to find out what was going on. He explained to me the situation and to put it in short terms he was over grandfathers for a cookout with brother and brothers girlfriend. Dad was watching football and was continuously asked why he won't come outside. Finally he had enough and decided to just go home.

Brother took offense to this and totally lost his shit saying to me how dad is an ass whole and when he sees him on the street he's gonna kick his ass and just totally belligerent. I called brother a drunk and he denied having anything to drink which is a lie but what ever. The night went from there with him going to my parents demanding things and saying they are not welcome at my grandfathers house anymore blah blah. Appear you dad said something he shouldn't have that just made things worse and it escalated from there. No physical violence took place aside from brother threating to get people to go after them which he won't really do and a lot of things were said out of anger.
<bot>: I was dragged into a situation I had nothing to do with and no knowledge of that ruined my dinner and basically kept me awake all night when I had work at 5am.