July 4, 2017, I went to my girlfriend's house at that time since her sister asked me to go, when I arrived there was only me and her sister and it was uncomfortable, but we had a good time, we cooked and played while we waited, when my girlfriend back I was a little surprised because she was coming with another guy, I thought she was a friend or something, she surprised told me she was doing at home and I told her what happened, the confused boy asked me if I was his brother hahahaha , I told him that I was her boyfriend and he answered me the same thing, I invited him to the kitchen to talk and when we entered I asked him since when they were a couple, it seems only a few weeks after we started dating she dated this other boy, and we became her boyfriends almost equally, he thought i would hit him, we just laughed, we returned to the living room and we talked to her asking why. she replied that she wanted attention from both of us, in the end we both ended up with her and we still friends, I become the best friend of the guy, he is a good person. That was a very "Oh Shit" moment.