I was on vacation this week and was already ill that the place I used to go as a kid had become another booze hub for young "adults". The waitress set a family next to us, and there was an elderly woman with them. She commented very lightly to the rest of her family that "she was cold". The father in a loud condescending tone quipped back at her "MOM, calm down! We'll get your sweater in just a minute!". This type of dialogue continued for a little while. The old lady asking very quiet and calmly, the "father" shouting back and talking down. I eventually had enough, looked directly at him, and said "Are you going to quit being an asshole to your mother!?!?!" TL,DR; He jumps up, gets right in my face and is yelling at me in front of my family. I just told him to "go for it", but he wouldn't. Finally it comes out that the woman is his mother-in-law, and the wife tries to defend her prick of a husband saying "she can't hear well so they have to be loud." I told her it was about tone, not volume, while the restaurant seated us elsewhere to avoid further confrontation. Hours later and it's just him and his daughter still sitting in the same spot. Wife and MIL nowhere to be found. Guess she finally understood, or at least I hope she did.......