Hello. I'm currently working through a situation that has me feeling very lost, rejected, and sad. I'm not going to get into every detail but I'll give the basics- I met a guy from an online dating site a few months ago. He initiated contact and pursued me. The first time we met we really hit it off. We had so much in common and got a long really well. We saw each other pretty regularly for the first few weeks. We had a lot of fun together. Things progressed and we became intimate. I really felt like he liked me and cared about me and I had strong feelings for him so I thought that it was okay. After that he became distant and although we texted on and off, I didn't see him for 3 weeks. We then planned to hang out but he tried to break plans with me the day of, giving me a lame excuse that was obviously a lie. I sort of called him out on it and we ended up seeing each other that night, he acted very affectionate towards me and again (now regrettably ) we became intimate. After that he didn't call me for a few days and I was in a really bad place emotionally. I ended up crying to a friend who told me that she saw him out with another girl (kind of a long story.) I also noticed that he had posted a picture online and tagged this same girl in it. I finally built up the nerve to confront him. He admitted that he is also seeing that other girl, that he had met a little before me. I told him that I didn't want to be the "back up girl" and he told me that he really liked me but decided that it's best for him if we just remain friends so that no one would get hurt. (too late.) I really trusted this guy at the beginning and let myself fall for him. Now things have ended and I'm having a really hard time.

Why did he do this? What was the point in pursuing me if he was seeing someone else before me? What was the point? Ugh. This really sucks.