How can I calm the situation when my mother and sister are violently arguing without the situation backfiring at me?
The other day, my mother and my little sister (17 years) were arguing (my sister didn't wanted to do what my mother wanted her to do because of X) and the situation was getting a little out of hand. In fact, I was worried things were going to degenerate.
This isn't the first time this kind of violent arguing has happened and I never know what to do to make everyone calm down. Most of the time, I just change place in the room and just stand, looking at them, hoping they will notice me (I guess I'm trying to silently say "I'm here, I'm watching you, be careful with your words and, please, stop arguing").
Example of the last time my mother and sister were in an argument:
My sister was watching a TV show on her computer. My mother wanted my sister to accompany her at X so that my sister would do some sport (instead of staying at home all day). My sister didn't wanted to. My mother got really mad (overreacting like she was having a mood swing) and tried to take the computer from my sister's hands by force. In the meantime, my mother was saying in an angry voice:
You spend to much time in your computer, you are going to come with me!
How can I use to defuse the situation without them getting mad at me for saying something?
I just want them to stop arguing so violently and start talking/negotiating like civilized people.