<human>: My fiance and I have been together 5 years. We have always had a good relationship. We were in an LDR for 4 years and have been living together for 1 year. 

Back in February, he started a friendship with a female (The girlfriend of another friend) They were texting constantly. I found out because I saw her name pop up on his phone and when I asked him who he was talking to, he said "people". It was hell from that point on. I was so furious because he hid it from me and I began to have trust issues with him. He told me he was sorry, and he didn't know how Id react.

When he talks to her, I feel completely sick to my stomach. I asked him not to talk to her because of how it made me feel and he did not go for that. He said, "he wouldn't let me tell him what to do or walk all over him." 

Luckily, a month later they stopped talking because according to him shes immature and dramatic. (DUH SHES 19) 

Now, They have started texting and facebooking like school girls again I don't trust the situation. He explains over and over that he loves me and only me and shes just a friend and they have good conversations. 

We are just now finally getting back to a good place in our relationship and he brings her back into the equation. I don't get it. 

I don't know what to do. Everyone tells me to leave him because he knows how much it hurts me and he doesn't care enough to stop talking to her. I love him very much and hes never done anything like this before. I know for a fact hes not having a physical affair with her, but something about this situation doesn't sit right with me.

Summarize the given text in a few sentences.
<bot>: Fiance has a female friend he texts frequently. (Every night) and I don't know what to do about it. He refuses to quit speaking to her.