<human>: Can you give me a shortened version of the text?

My boyfriend and I have been dating for 3 months. Three nights ago, he called me by another girls name (let's call it Cindy). I brushed it off and even made fun of him for calling me that. However, he vehemently denied even knowing a girl by that name and said how weird it was that he ever said that. 

I thought that was the end of it, but last night we were both on his phone and I saw the name "Cindy" pop up on his phone. I immediately asked him about it and he initially tried to avoid talking about it, but he eventually told me that he had a fling with this girl last year and he didn't want to tell me about it. 

Cindy lives in a different state, so I am sure they aren't having a physical relationship, but I can't help but think there's something to hide if he lied about it. He's visiting her town in in a few days for several weeks and before this happened I had no reason for concern, but now I can't help but be a little nervous about it. He has sworn he isn't cheating/would never cheat on me and says that it's just instinctive for him to lie and deny things when he doesn't know what else to do. 

I'm not really sure what I should do or say to him. My friend told me to tell him to cut all contact off with Cindy, but I don't want to seem controlling. I don't want to break up with him over something like this, but I don't want to act like nothing happened because I was rather hurt by the fact that he continuously lied to me.
<bot>: Boyfriend called me by another girl's name, lied about knowing a girl with that name, and I'm not sure what to feel.