Odd Relationship With Ex

First of all, this is a very long story so bare with me!

I was in a relationship with my ex-fiance for about 4 years. We have 22 month-old child together. We had a rocky relationship, full of ups and downs. The goods were great and the happiest times of my life, while the bad was just horrible. We decided to call it quits for good about 6 months ago.

After the break up we continued to see eachother on a daily basis and got along for the most part, and we even had sex a few times in the following weeks. In late October/early November she began talking to a guy on facebook whom she went to high school with. He lives in Chicago, we live in SC. They began a relationship even though they hadn't seen eachother in 14 years or so. The guy eventually came to visit her for a few days in December and I spoke to him briefly. I was a little bothered by the relationship as I was still not completely over her but it wasn't affecting me that much.

At this time I also learned that my ex planned to visit him in chicago for new years and was taking our child with her. She did not tell me this, I happened to find her flight information sitting out. She purchased tickets a week after she started talking to this guy on facebook and was not planning on telling me about it, atleast not until the last possible moment. We had a disagreement about it as I did not want her to take our child.

Fast forward a few weeks, around Christmas she informs me that she is not going to chicago because she is worried about taking our 1 year old on a flight for the first time. The following few days after Christmas I contacted her everyday to see our child. She kept coming up with excuses and saying that today was not a good day. After 3 days (I was used to seeing our daughter on a daily basis) I went to look for her. She was not at her apartment and I even went to her parents house and spoke with her sister. My ex decided, without informing me or giving me any heads up, that she wanted to move to chicago to be with this other guy and took off, with our child, a day or two after christmas. I was devastated and soon filed papers through the court to have her our daughter returned and establish custody.

My ex ended up being in chicago for almost 2 months. While there she would skype with me ever few days and tell me how happy our daughter was and how both of them loved it there. She wanted me to come visit them and could not tell me if/when they would be returning. I had already hired an attorney, and being a full-time student and working full-time, I was in no position to travel, not to mention I thought it was a slap in the face. About a month ago, before I could serve her with papers, my ex informs me that she is returning home and that I was right about everything. She came back that weekend and was subsequently served with papers at her apartment a few days later.

Here's where the story starts to get strange. In the days/weeks after my ex returned home, she began sending me major mixed signals. I assumed that things didn't work out with the guy she was dating, and was hurt because I was taking her to court. She would act very defensive to me, then turn around and say that she wished we were a family and would cry and embrace me, etc, etc.

About 3:30am the day before we were scheduled to appear in court I get a phone call from her. I just happened to be up because I had to be at work at 5am. She asks me what I'm doing and asks if I will come over and bring her something on my way to work. I found this really bizarre but I stopped by her place anyways. I asked her what was going on and she was giving me the impression that she wanted me to make a move on her. I resisted the urge (or atleast tried to) and went to leave. She embraced me on the way out and started kissing me. At this point I couldn't fight it and we were all over eachother which eventually lead to us having sex. Even after everything that had happened, I really did miss her and still had very strong feelings for her.

Things were awkward the next few days. We ended up coming up with a mutual agreement concerning custody/visitation and had it signed by a judge. We even hung out the day we were supposed to be in court and took our daughter to look at puppies and spent the whole day together. It was very strange considering what was going on. My ex started to tell me about how she didn't think she was supposed to be with this other guy and all this other stuff. She also told me that she did not want to be with me, which I understood and agreed.

Since court things have just continued to be weird between us. I still see my daughter everyday, even though we have a set schedule. I spend a lot of time with my ex, sometimes she asks me to come over or meet her and sometimes she acts like it bothers her that I'm around. We've had sex twice since last saturday. Once she had went out with friends and had a few drinks and came home where I was keeping an eye on our child and basically told me straight up that she wanted me. The other time was a few days ago and just happened while I was at her place.

Now, of course all of this is bringing back feelings and emotions and really confusing me. On top of that she has still been talking to the guy she was previously dating and even plans on going on vacation with him to New Orleans next month.

Here is my question.. what the hell is going on in her head and what am I supposed to think of all this? I still love her very much and if I had the choice I would be with her, but I also know that it would not be wise for us to jump back into a relationship and we have mutually agreed that we aren't going to do that. Also what about this other guy? Do I tell him whats been going on or do I keep to myself? My ex has been acting extremely paranoid lately and swears that I am trying to get all in her business and has even accused me of hacking into her computer. Obviously this is because she thinks I'm going to tell this other guy that we have been sleeping together.

Basically so much has happened in the past few months that I don't even know what to make of anything anymore. I just want to have a strong relationship with my ex and be able to parent together, but the intimacy is really complicating things. I really want to be able to get over her, because I know this kind of relationship is extremely unhealthy and is just going to lead to more problems, but at the same time I can't help how I feel and I am still very much attracted to her. What am I to do?

Sorry for such a long post, I may have went into too much detail but I felt it necessary to understand exactly whats going on. Any thoughts/advice is appreciated!