with a girl like you

one of my coworkers, whom i’ve nicknamed HIM, recently has started speaking to me again. The reason why this is remarkable because our relationship is damn fucking weird. Shortly after he broke up with his girlfriend of several years, he started hanging out in my cube. Then we started hanging out for lunch, going to have sushi. we would email each other every day and went back and forth for awhile, even while he was dating gf #2. Then gf #2 and he broke up and he kept bugging me to go clubbing with him (like that would go over well with paul! hah!) and then gf #3 came into the picture. My birthday party was a few weeks ago, and I invited him to show. He said he was and RSVP’d that he and the gf were going to show up. They never did.
It bothered me that he didn’t show up. I couldn’t figure out why it bothered me so much but I think because I thought we’re being friends or starting to be friends. I feel so awkward socially sometimes and I can only attribute that to the fact that I don’t go out with Paul at all, and our social circle is short.