Is OTHER wrong in the post ? POST : I have two really close friends that recently had some drama. Henceforth FA (friend A) and FB (friend B).

FA had been in a relationship with this Absolute trash human being for around a year. The guy was extremely emotionally manipulative.

The ATHB had said he wanted a break.The Catch: He was a cheater. He would tell this spiel to other girls about how his current gf was cheating on him and he couldn't bring himself to leave her ectect. Bullshit.

So FA eventually found out from the girls he was texting that he was doing this (BTW most of them were her friends) She confronted him, he apologized and guilt tripped her into waiting for him to get his shit together.

FA waited and waited. Eventually she started to realize how full of it this ATHB was. She dumped him officially. No more breaks. Another guy immediately started showing interest in her and ATHB throws a fit about her being unfaithful and doing this to hurt him.Just a manipulative douche. He did things like crying in front of her saying he was depressed and begging for her to forgive him.

The whole time this was going on FA had been venting to me and FB. After FA official dumps ATHB he follows her around like a kicked puppy trying to guilt trip her.FB then explains to me that ATHB has been talking to her and she's starting to catch feelings. I immediately shut her down and let her know that is a very bad idea. FA's wounds are still extremely fresh and ATHB is a douche.

So FB “takes my advice”, but I noticed her getting extremely close with ATHB. So now FB was following ATHB around like his kicked puppy.

I bring this up to FB and ask what's going on. She tells me that she has been friends with ATHB for a long time. She sympathizes with him because she knows his side of FA and ATHB's break up. Also FA is starting to see another guy. FB makes the argument that FA must be over ATHB so its okay for FB to date him. This is a bad idea.

Everyone knows what happened between FA and ATHB. FB is going to look extremely bad in front of her peers for some douche that will treat her like trash. And it's just a plain douche thing to do, date your best friends ex. That's a big NO.

FB goes behind FA's back and starts dating ATHB. I was one of the last to find out and it really pissed me off. The fact that FB didn't tell me and that she completely ignored my warnings.

FA was very distraught and it was a blow to her already fragile self worth. She was insecure that maybe SHE was the problem. If her best friend chose her ex over her, was her ex really the bad guy? 

It was really painful to watch and made me more angry at FB. The relationship between FB and ATHB lasted a week before she realized that what everyone had been telling her was right.

FA and FB haven't spoken in weeks and FA recently gave me an ultimatum between them. I don't feel like I can trust FB anymore. I want to just cut her off.

Would I be the asshole for abandoning my friend who broke girl code?