I was with this girl since senior year in high school. We were together for 5 years and in our early 20's at the time of this story.
My girl was being distant for a couple of months. Every time I questioned why she was doing certain suspicious things she'd blow up at me saying that I was being jealous and paranoid and I need to calm down.
I noticed this guy was liking a lot of her pictures and every time she put up a new pic he would be the first to like it. I ask her about it she blows up and takes me off her FB for stalking her FB. Obviously by now I have an idea of what's happening, but this girl was my first everything so I really didn't know how to handle the situation. She would disappear late at night a lot and not text me or call me for hours after she got off work.
One day I just finally decided I needed to know what was happening so I waited for a Wednesday when she would typically disappear on me and I insisted that we should go out and watch a movie or something and she was super insistent on not going out and that she was feeling sick. I insisted that I will bring her food and we can just watch a movie together at her place and she insists "NO!!! I'm sick I don't want to get you sick" so I kind of got a feeling that something for sure was happening that night. So she of course disappeared on me on that night and I decided to camp out outside her house at around midnight(when she usually would end up texting me saying she just came home and fell asleep after work and she just woke up) and I'm sitting in my car just waiting to see what's going to happen. Her dad left for work at 12:30 AM anyway so if I didn't see anything I'd at least see if her car was in the garage. Then I see a white Camry driving down her street toward her house. It stops in front of her house. She gets out and walks to her door and as soon as she gets inside I get a text saying "sorry my phone was dead and I was watching a movie on netflix with my parents and I was too lazy to go upstairs to charge it" I was heart broken. I forgot to mention that I borrowed my friend's car to basically stalk her house so she wouldn't recognize it. As soon as the guy dropped her off I chased his car and caught up to him at a stop light. I looked over and it was the same guy that was liking all her pictures who also turned out to be a coworker of hers.