Instructions: 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: Well this happened a few hours ago.
Today I spent most of my day with my gf
(From 9 am until 5 pm)
When I left, I told her that I was going to spend most of my time at home. But that was a mistake because later I went to my friend's (F) concert where she was going to play the Violin.(Actually I didn't want to go to that concert and that's why I didn't tell my gf that I was going, but well...)
Now when I was going out of the place where my friend present my gf sent me a message asking what I was doing.  I told her that I was just leaving that concert
Well, I think at that moment things went horribly wrong and she just stopped replying. After some time I asked her what happened and she told me that she was angry because I didn't tell her that I was going there.
Right now I'm pretty confused about this situation, so I just want to now. AITA? 
Output:
not telling my gf I'm going to a friend's concert