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: So a few years back I was hanging out with my best friend's brother (we'll call him Adam) who was just going on and on about how much of an asshole my friend (We'll call him Billy) was. I asked him if he really believed that stuff and if he wanted to reconsider his words given the severity of the accusations and the fact that he was talking to somebody who is definitely not amused by this. He said that he really believed that his brother Billy was an asshole, a stupid, arrogant douche and other insults like that. After we got done talking, I told Billy what had been said and he decided to cut off all contact with Adam. 

So now, five years down the line, Adam has had a few kids, and has tried to patch things up with Billy, in order for the family to be cohesive and get to see each other. This year, Adam and Billy's parents, who are divorced, put aside their differences to have a family Christmas dinner for the first time in over a decade just to be with Adam's kids. Billy was invited but opted not to go because he's still mad about what Adam said all those years ago. 

Given the situation, Billy is now blaming me for cursing him with knowledge and ruining his chance to see his niece and nephews grow up, because it's my fault that I told him what Adam said. He's threatening to end our twelve year friendship over this and I am wondering if I'm really at fault.  

So tell me, reddit, AITA?

telling my best friend about his brother's shit talking and ruining their relationship