My wife and I are from two different cultures and we do not share the same first language. We talk in English but with her family, she talks in her language.

A few weeks back, I was getting ready to leave for work and my mother in law, was sitting with my father in law and they also had my brother in law in the same area. She said something in her language and my father-in-law spoke back in a tone that was not pleasant but he was trying not to sound rude. I was wondering what that was.

Then my wife came in and my mother-in-law and her started arguing. My mother-in-law was laughing while my wife asked me to get out of this place. As we left, she turned around and says to her mom "Disgusting!" in English and slams the door. I did not ask her because she seemed very annoyed. They had kept in intentionally in their language so that I do not hear and I did not want to invade that privacy.

My wife is not talking to her and when I asked what happened, she told me that her mother had said that I have a butt that really pushes its shape out of the pants. Her husband has said, "Stop this. That is your son!" Then my wife heard this and they both had an unpleasant exchange.

It left me wondering, was that a joke? When I was in my teens, my mom would ask me to pull up my pants because I used to wear them so low in my butt that my underwear would show. "Your butt is sticking out" is what I have heard from my mother in that context, meaning dress appropriately when you go out. This was not the situation as I was fully dressed and ready to go to work.

I am wondering, is this was said in a sexual context then why in front of her husband and her daughter only to get snubbed by both? Was she trying to make her husband jealous? If that is the case then why use me when I am married to her daughter? My wife is upset and now I am feeling very very uncomfortable.

Does anyone have any logical explanation other than something really sick and twisted?

tl;dr My mother in law said that my butt is sticking out.