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: A friend has recently cheated on his gf when he was drunk. His gf suspected it when I got home alone and asked me about it, so I told her what I saw, nothing more, nothing less (my friend kissing the girl at the club and then them walking out together). It's not my job to lie to her because my friend fucked up. He later confirmed to me that they really had sex. 

I'm not exactly religious, but he knows I have principles, and that I don't associate with cheaters is one of them, so I told him he could fuck right off. He then called me an asshole for not helping him as a friend and telling his gf. AITA?

giving up on a cheating friend