A couple of weeks ago, at the foodbank, my brother discovered that there was a small group of people bitching about everyone. They got pissed. 

One of the girls sort of isolated herself for a bit and everyone was going on about, wow, she's such a b****. She's so two faced. She comes today and my sister is talking to her like they are best mates. Like of course, I didn't want them to argue, but exactly the same thing that they were getting annoyed at her for doing. I think it is better to actually address the problem - like say, why did you say those things - as opposed to both sides being so two faced and chatting shit behind others back but being best friends together. I'm sorry. I was so annoyed by how superficial it was. My sister's boyfriend - who was also commented about by the girl - just ignored her. I mean, it is getting no where with solving the problem, but at least he's not pretending to like her then saying stuff.