Work drama

Hello, I need some advice. I dated a guy that i work with (big mistake). It went really really good for about 5 months and i started to develop feelings for him. Well all of a sudden i started to notice a difference in the way he treated me. He stopped calling, returning my calls,texting and he started to avoid me at work. I would ask him to have lunch or walk to get coffee with me but he started saying that he was too busy to leave his desk.I finally asked him if anything was wrong and he gave me some lame story about he didn't think he should be dating because he needed to focus on his son and selling his home. I can understand that because he is a single father and doesn't get much help from his ex wife. I decided to give him space and not try to push anything. Well about 2 months later i asked him if he wanted to hang out sometime and he gave me the same excuse. Well a few weeks ago i saw on facebook that he was tagged at the park with a girl that we both work with. Now I keep seeing them together at work having lunch, going on walks around the building, coffee, etc. I can tell that he is really uncomfortable whenever i run into the two them together. I just dont understand what happend and why he would date another girl in front of my face. I know 5 months isnt that long to be in a relationship but i'm really hurt and i go to the bathroom and cry everytime i see them together. I'm not an insecure person but i keep trying to figure out what happend. I hate this feeling and want it to go away.

His actions have spoken. Rather than look inside this guy to see what made him tick, you looked at the outside only. Okay, 5 months isn't really any length of time to really get to know someone but once you developed feelings for him, he turned the other cheek. He needs to be over his marriage and his ex wife, and if he isn't, then your workmate will receive the same treatment as you did. Regardless, if this guy was any sort of a man, he would have prevented the relationship he had with you from developing into something that he had no business being in. He gave you a lame story about why he shouldn't date you and that should tell you how much of a lame man he is...it's that simple. He has dented your self esteem and he has hurt you with his selfishness. You need to look for a man who will respect you for who you are but that's your choice to do so.