Thanks for all the advice

I agree with your ex. I think you have become obsessed over his friendship with her. She certainly doesn't seem to be making moves in his direction for a romantic relationship. The quote marks around "lesbian" are interesting and thought provoking. And you see "passion towards her in his eyes"? You really see that--or you WANT to see that? My vote is you are wrong.

Does he want to try again with you, or is he okay with the split?

I will agree with Wondergirl, she was a friend, most likely nothing else. It appears you never liked the friend and looked for reasons, I say you were wrong

No he's not okay with it. He wants to be around and get back together I'm just not sure I want to. You don't think it matters they have been together before, and he's been known to cheat with her? It's not that I don't like her, we've worked together and known each other for a long time. I've hung out with both of them together and I chose not to anymore because they were very touchy and I didn't like it. However, one point of the story that I forgot to mention is that he wasn't okay with me hanging out with a friend I had for years because we had slept together before. I quit doing so out of respect to him since it made him uncomfortable.

So you don't trust him, that is the end of story, if you don't believe him and trust him, then just leave. Let him move on.

I am great friends with one of my ex's, we talk all the time, then go for a few months and never talk. She needed to borrow a little money and I helped her out. We have issues, sometimes we talk to lesson to the other.
You just don't trust him, no real evidence or reasons, just jealous of the friendship.

** that is how you sound in he writing of the post anyway.

I might tend to be jealous of his time with her, nothing else, if he spends more time with her than you.

I suppose it's possible that she senses the thrill he had over his 'conquest' and is leading him on as a way to keep him around when she has no partner, and he is actually attracted to the thought of converting her. That might be the passion in his eyes. Not so strange. Many men dream of converting lesbians. Many women dream of converting gay men. And for many, the conquest is the only goal. Then they lose interest immediately.

If he wants you back and you are torn, why not have a real heart to heart about his feelings? And you tell him just what concerns you too.

When we cannot talk and reach a resolution that works for both partners then its best to just separate, and go our own ways. Especially when they ask you to do something they are unwilling to do themselves. That's a double standard.

If talking didn't resolve things, I fail to see the point of getting back in the same situation, with the same guy.