Kid having step dad problems mom pretending it's happy family

One of my best friends (Z) has an 10 year old daughter Y. Z has been a single mom from Ys birth until she was 7. Y and I are really close. I lived with Z and helped her out until Y was about 4.For father's day weekend, our families hung out at my house. When Y got here, I could tell she was upset. Z said that before they came over, they did a little at home father's day celebration with her husband. Y didn't want to because she doesn't like her step dad. Z wanted Y to pretend like her husband was Ys dad and it was a happy father's day. At first, I was just thinking that this was normal blended family issues. I tried to not get involved because I didn't know the details.This past weekend, I was babysitting Y for the weekend. She mentioned that she hates her step dad. I asked her why. She said that he is keeps screaming that he wants her mom to spank her. That everytime she talks he tells her "children should be seen and not heard" . If she keeps talking, he will say she is being " disrespectful and should be spanked". That he tells her "your a kid and your opinion doesn't matter". When his son (same age) came over, the son lied and said she did something the son did. Step dad and Z got into a a fight because step dad wanted to spank Y. When he found out his son did it, he didn't spank him.Y said that when he gets home from work she goes to her room and only comes out for dinner because her mom will either guilt or scream at her.I have been best friends with Z since 3rd grade. I know she doesn't believe in spanking and that "children should be seen and not heard". I know Y was almost never told to not talk when I lived with them.Z told me Ys grades a slipping and she has been acting out more. Part of me thinks this is why.I would like Ys situation to improve. IDK if this classifies as abuse. Y says she hasn't been spanked. I think step parents are allowed to spank kids here. Even if he doesn't, I can see Y is stressed out about he saying he wants to.Is this normal blended family issues? Is it ok, and should I let it go? I haven't heard the step dad's side. As an "outsider", am I intruding on their family? via /r/Parenting https://ift.tt/2nTdcfZ