What do I do?

OK so..... theres this guy. And he's never really liked me as more than just a friend. I'm the best friend actually. I have been for a really long time. And I don't want to do anything to fuck it up. Lets call him..... Joe.

So Joe dated this really good friend of mine a really long time ago and she.... lets call her Jane..... was his first love so he's never really gotten over her and he never will, it's just one of those things. Since they dated each other, they have been on and off with other people throughout the past 2 years. Actually, Joe found someone else he loved just as much if not more than Jane, just a different kind of love. But she.... we'll call her Jess..... was a total control freak. She didn't trust a single thing John did and reminded him of every thing he hated about himself.... some girlfriend huh? But for some strange reason I'll NEVER understand he still loved her and he put up with it..... for a while. One day, Jess decided she couldn't take the fighting anymore so she ended the relationship. Then, 2 minutes later she called back saying JUST KIDDING..... but John said no. And that was that.

So about a year went by. I have my suspicions about Joe and Jess being friends-with-benefits because she NEVER left him alone and things were bound to happen with all the teenage hormones flying everywhere.
Everything kinda stayed quiet. Jane is dating other people, Joe would feel to guilty about dating other people because it would hurt Jess, and Jess is..... well, I was never really that close with Jess so I don't really know what she was doing. Then the glue that held our group of friends together, and my BFFL moved away (I miss her so much) and everything started to fall apart.
I got really sick of Jess treating Joe like total crap and they weren't even dating so I decided to tell her how much of a bitch she was, and my currentBFF (who's amazing) backed me up, as well as Jane. So, Jess was completely removed from our social circle THANK GOD.
Joe wasn't entirely thrilled with this but I told him choosing sides was out of the question so he was pretty mutual.
Months past and currentBFF and Joe drifted. Jane got a really great boyfriend but before that happened, Joe told her he still liked her. Jane did not have the same feelings. So now he's back with Jess, who apparently swore the fighting would stop but is showing signs of coming back to her old ways which will make Joe even more depressed because he's with his second choice, and seeing Joe depressed makes me depressed......... Wow, my life is fun.