I am 26 and I live on my own in a city about an hour away from my parents. My sister currently lives with my parents and my little brother back home. Lately, she has been reporting some very unreasonable behavior from my parents. My parents are from Mexico and have some very sexist beliefs to put it bluntly. For example, they think it is inappropriate that my sister stay out past 9PM stating that decent women do not stay out so late.

Anyway, my sister has been getting into escalating arguments with my parents usually precipitated by their unreasonable beliefs. For instance, back during New Year's she asked if she could spend the holiday with her boyfriend's family in Texas. My parents (specifically my dad) accused her of wanting to run away to get married with him. At the time I advised her to forgo the trip to keep the peace.

I just woke up to go to the bathroom and I saw several missed calls and text messages from my sister. Apparently, she has been working lots of hours at her job and did not come home during the weekend. My dad reportedly came into her room and yelled at her for not coming home. When she said she was working, he demanded her boss's number to confirm the hours she was working. He then accused her of not contributing to the house or doing anything, even though she let my mom borrow almost $800 over the weekend to help with (which I know is true because she transferred the money to me to pay the bills using the online accounts)

My sister rightfully countered that my dad was being unreasonable in his demands. My dad then said that the house was not a hotel and that if she wanted to have her own life then she should do it. He also reportedly said that she was a disappointment and that he wasn't proud of her.

While technically not officially kicked out, my sister is currently staying at my aunt's house because of the tension in the house. She is currently asking for my advice, and I am not sure how to approach the situation. I'm at the point now where I think I need to intervene because (if true) my parent's behavior just seems out of control. At the same time though, I realize its my parents house and their rules and also that there are two sides to every story. I am inclined to believe my sister though because when I lived in the house I witnessed first hand my dad's wild accusations about her wanting to run away to get married and what not.

**TL;DR;** : Parents are engaging in what I see as unreasonable behavior and demands against my sister. Not sure if I should intervene on her behalf or how. How should I go about this situation? Should I confront my parents about their behavior?