Well, I can tell you just my experience.
My wife and mt sister in law, the wife of my brother, are always arguing and really dislike each other.
Sadly for me, they had a lot of verbal brawls but didn't fought yet.
Some time ago we was together in the beach and the girls did a race running across the beach.
It was not a fight, of course, but it was exciting for me to see, at last it was a competition betwen rivals.
A little satisfaction, hehehe.