Peer review

I just read Karla's story and I thought it was really good. I didn't see how Lupe could do that too Maria tho. See what happened was Maria and her boyfriend had been going out for the longest time and Maria's best friend Lupe was secretly fooling around with him behind her back. Lupe couldn't deal with it anymore and finally told Maria, and she ended her relationship with Lupe. The thing that got me thinking how is the guy not at fault for any of this? He was fooling around with both of the girls and the girls didn't even get mad at him.