Definition: Given a real-life anecdote of a complex ethical situation, generate a suitable title that describes the main event/root cause of the situation. Imagine that the given text is a social media post, and you have to write the title of the post, so the users can decide to read the main text or not.
Input: I've a nephew who stays home in the mornings as he has school in the afternoon. No one else is home during this time usually, as we had work. I happened to be home today as I took a sick leave for a bad headache. He wouldn't have known I was home till I came out.

When I came out of my room and I saw him jump and change the channel. I have a good view of the TV from my door. He was freaked out. Channels are normally locked. So he shouldn't be able to watch a channel that isn't kid friendly. So I asked him what he was watching that made him jump. He said he was just changing channel as I came out, and jumped coz he didn't know I was home. 

I stood there for a bit, making myself a tea in the kitchen. (It's a living room and kitchen combo) of He went to his room after a moment. I realized I can check what the last channel was. It was an inappropriate channel.. and a really inappropriate movie. I have no idea why that channel wasn't locked. (Most channels were locked) I texted his (step) mother immediately.  She came home and gave him a lecture. He kept saying it just happened to turn to that channel. 

His (step) mother thanked me for telling her. He on the other hand, is very angry at me. His father came home as well, and he was annoyed at me for making an issue out of it. His words were "mind your business"

AITA? Should I have done nothing? 

telling on a 9 year old for watching 18+ rated movie