<human>: Can you provide a brief overview of the text?

My boyfriend and I have been together for three years now and six months ago we decided to try an open relationship. It was something that had been brought up in a drunken night that was immediately shot down by me. I've always been a very sexual person though so the more I thought about it, the more the idea grew on me so I asked him for an open relationship which he was fine with, he just wants me to be happy. 

Fast forward a few months and I've been with quite a few guys and he still hasn't found a girl yet. He then tells me last night that he has been talking to this girl for about a week and they're going out tomorrow(tonight) and then going back to her house to watch movies. 

I don't know why but this made me extremely uneasy and gave me a horrible feeling in the pit of my stomach. I just don't know how to explain it to him. I don't want him to think that I'm being selfish, sleeping with other guys only to change my tone and not want him to sleep with other people. I'm honestly okay with the sexual sides of things, I'm happy for him and I actually find it rather hot that he's going to be with another girl. I think the side of it that makes me uncomfortable is him developing a friendship with this girl and texting her all the time like he was yesterday. I was put on the back burner all day because he was constantly texting this girl.
<bot>: Boyfriend and I are in an open relationship and he's finally taking advantage of it but I'm not as okay with it as I thought I would be.