He wants to sleep with his friend

From the start my boyfriend and I have had a weird relationship. He's told me I can sleep with other people as long as I tell him because he gets off on hearing stories and watching, if he can. However, I don't feel comfy with him sleeping with anyone else. It leaves a sick feeling in my stomach.
He feels like he's wasting his youth though, cause he was a real "player" in college and he loves to flirt and sleep with girls. He's made his choice that he's going to stay with me and loves me.
A week ago he confessed that a few months ago when we were having a big fight he had kissed his friend when she came onto him. He describes her as being a very hard to get person and was surprised when she did it. That very same friend, I am suppose to sleep with soon and he's rather jealous and said he wants to sleep with her and it would only be a one time thing. At the time I made stipulations that I felt made it comfy for me to let him do this since I was getting to sleep with her and it would relieve some of his need to want to sleep with others.
Now, however, I'm starting to feel sick about it. She doesn't know him and I are together. She think we're just friends with benefits.... And when I think of him going to her and sleeping with her I just hurt and feel so sick and I want to call it off, but I don't want to go back on my word. I'm not sure what to do anymore.

tldr; my bf wants to sleep with his friend that I'm going to get to sleep with first and I agreed to let him, but now I'm starting to feel sick about it.

Ellimity, you're going waaaay out of your comfort level for this guy - and I can't help but believe it's going to end in tears. Is he really so much worth it?

Is what you mean by you "sleeping with her" the same as what he means by it?

If you aren't comfortable, let him know it. You don't want to do things you're going to regret.

Hmmmm, well anything that leaves you anxious to the point of feeling sick has no place in a healthy relationship. That being said, you can't really expect to be able to sleep with other people and deny him the same freedom. I am not sure how long this dynamic is going to work out here

Yeah, I have to say that I was a little bit confused by your story. So, are you saying that you sleep with other people outside of the relationship as well? If that is the case, then I would definitely agree with Nicole in that you can't do that but then in return be upset if/when he does. If you want an open relationship, it has to be open to both sides.

All the same, if something makes you uncomfortable (especially to the level this seems to) then, as Nicole said, it has no place in a healthy relationship. So, all you can really do is talk to him about it. If you are going to have an open relationship, then you need to discuss and agree to appropriate boundaries to do so while still keeping you both happy. If you are not happy with an open relationship at all, then you need to be honest about that, and decide together if you both can live with monogamy, or if it might be better just to end things. Good luck to you either way.

Dump him, he doesn't love you, he is using you for some game.
If he loved you he wouldn't be ok with you f ucking another or want to f uck another himself.
Wrong wrong wrong!