I'll try to keep it short. Both me and my girlfriend were with our own partners when we met. We met, fell in love, wanted to be together, decided to leave our previous partners and start a relationship together. During this period, we were seeing each other and had sex once. We both didn't meet our own partners, as they were both in different cities at the time. In a few weeks, I talked to my ex on the phone, and ended my previous relationship. She said she would meet hers in person to do the talk. I had no bad thoughts and had trusted her, so I said ok. That day in the afternoon, she called me and said she did the talk, it wasn't easy, he cried and insisted on not to leave etc., and they had sex two times. I didn't think about much on how to react, maybe I was a bit shocked, but I really loved her and said it was ok. But when she said she may have to meet him again to end it, I asked her not to meet and end it on the phone just like I did. She did that, and we started...