So Confused!

I am a firm believer that it is unhealthy to tell your spouse who they can or cannot be friends with.  My ex took that liberty to the max and figured I wouldn't tell him who or who he couldn't be dating either, and when he gave his other girlfriend the house number that was the end of that.  My mum thinks that should of ruined my thinking about friends but it didn't.  I don't want Joey to tell me who I can pal around with so I won't tell him who he can pal around with.
 
In enters Candace.
 
I have never met her, she has a travelling job that takes her through our city about once a month.  Joey met her online years ago and they flirted on the phone and online and went on a few dates but nothing ever came of it.  That's what he told me.
 
About two years ago we had a fairly serious fight.  He ended up going to his cousins(who is married to my best friend) and 'cooling off'.  I later found out that he had text this Candace girl and asked if she would meet him somewhere for coffee or something. Thankfully she was out of town at that moment.  That hurt, alot.  It bothered me that he would run to this girl when we were arguing.  But I bit my tongue, I told him flat out that I didn't like her but I wasn't going to tell him to cut ties. 
 
He stopped talking to her on his own free will.  Or so I think he did.  Anyway, my cell phone broke about three months ago and we have been sharing his as we have no land line.  I keep it all day and then we just leave it sit around when we are home.  I recently went to erase texts because he had soooo many it was crazy, I was just going to erase the ones from my family. 
 
Halfway through the list I came across her name.  I know I shouldn't snoop, and I hate myself for doing it, but I looked at it.  Over the past six months he has been texting her.  He always initiates it, but she carries on quite the conversation.  It seems innocent.  They talk about travel and cars and houses and such.  But not in a single text has he mentioned me or our daughter.  She asked him what was new and he replied that he bought a house and an SUV.  She asked him if it was a big house for just himself and he answered 'not really!'
 
I want to confront him about this, but it doesn't seem like it's gone above and beyond anything friendly and Joey has always been vague about answers so I could see him texting these things not thinking how they would look to someone else.  I don't want to tell him to stop talking to her, that would make her seem more desirable and I don't want to control him.
 
But now I'm worried about him cheating.  We have been together for five years almost, and he has never given me reason to think this.  I don't even see where he would have time to cheat!  But it's in my mind regardless. 
 
Argh, I wish this girl would just leave him alone.  Don't answer his texts.  I want to just text her and tell her to back off!  But that would be a baaaad idea!