left gf of 3yrs, and now I want her back she says we should take it slow

I recently broke up with my gf of 3 years a couple weeks ago, after doing so I moved out. I realized after I told her I was moving that what I had done was a foolish mistake out of anger at the time, when in reality we should have talked about our differences, I hoped that she would have asked me to stay and probably would have. I want to get back with her and we've been spending a lot of time together and she says she still loves me and wants to try to make things work but wants "to take things slow". However I noticed that shes been very talkative with another guy(a previous fling I'm told from 5-8 years ago) and when I had asked about it she says they have been talking for some while even before I moved out. I feel like this guy is getting in the way with her and I progressing, shes claims hes just a friend but I can see in her face and eyes its clearly more, I feel she's invested in him to an extent. To add to this big mess he's got no idea that I've been spending all this time with her. we had a bid talk about it, I told her how much it bothers me and she tells me that any physical actions are completely exclusive between the two of us, but she refuses to tell the guy that her and I are trying to work things out.

I am really stuck in a rut here because I whole heartedly love this girl. And after reading an article I can understand not jumping right back into the relationship where we left off but starting a new one with her may be the key to keeping her. One of her complaints of when we were together was that I didn't do enough romantic things for her and I agree with that. I realize where I went wrong in the relationship and so does she and out of my realization in the last 2 weeks I've completely changed my attitude around her, I do more stuff with out her asking, cuddle more, randomly buy flowers, send sexy messages, leave love letters around the house, and I even took her to the place where we had our first kiss, read her a love letter and I made her a scrap book with all our photos and gave it to her, and called it our 2nd first date, there were many tears.

I guess why I'm writing here is cause I would like to know if I'm going about this the right way? I've stayed at our house for just about the past week consecutively, not just because I want to(because I do) but upon her request as well. Now I think us spending everyday together is not taking it slow but in the same respect I feel more sound about her not going to see this other guy. With that said, I don't know how to react to the situation, her phone still has our pic on the home screen, we are still in a relationship on facebook even though no one can see it cause its private, she tells me she loves me daily, and we still make love. The part that throws me off though is I've seen some of the texts they send(I don't snoop she just leaves it open when were next to one another or responds right in front of me) and some are pretty sexual, do I approach this guy and ask him to back off or tell him the situation? Do I walk away? Or do I just continue with this just as it is and if there's love it will find its way?

And are there any other suggestions that may help rekindle the fire, I have faith that it's there, I'm just running low on options.

Thanks

Start dating other girls too, and do not feel guilty about sleeping with them. Even if you're sleeping with your ex, continue seeing other girls until your ex decides to put her name on it. Do not keep asking her about this. Either stop all contact with her, or start seeing other girls too. Right now she knows she's got you by the balls, show her you don't give a ****.

It's not your place to tell the other guy about the situation or tell him to back off. You see, he's only around because your girlfriend encourages him. She WANTS him in her life. If she was serious about wanting to rekindle with you, she would get rid of him.

Telling him to back off will do nothing to help your relationship - because it does nothing to fix the underlying reasons of her wanting him around.

Lastly, I suspect she is sleeping with him. People don't send sexy texts if sex isn't on their minds.

A part of me wants to just stop talking to her all together and the other part says stay and fight for it. It just sucks having to deal with it like this. Normally I would just go sleep with other girls but for some reason I can't explain I don't have the will to do it right now

Do you want to get back with her because of the challenge now that the ball is in her court?

You walked out for a reason. Sure you are being romantic now cause you are chasing her again though if you got her back & she told the other guy to move on I wouldn't be surprised if you walked out on her again or have gone back to your old habits.

No I genuinely love this girl, normally I could just walk away but there's something telling me keep her. She's a good girl we've had amazing times together but we've had our share of downs as well, nothing that a little work couldn't fix. It's just going about it that I'm having trouble with I feel she loves me but I can always tell when she's distracted by this guy. Knowing how I feel now I don't think I could leave her again, instead of making rash decisions I think I'd take the time to air and talk about whatever problems arise. I just don't know what's holding her up?