Reality check me? In disbelief and shock/ disgusted by my fiance?

[Renmarie]

I'm 27, I have a 5 year old from a previous marriage. I have been dating my current (well, ex) fiance for 3 years now. We got engaged last year.
We're an average couple and we don't have many problems and arguments. We spend a lot of time outdoors and having bbqs, ice skating, we get out when I have a babysitter.
My fiance is older than me, he is 45. He has never been married or had any responsibility other than himself and his car/house payments (him and his twin bachelor brother own their house).
He is well respected in the community and is known as a hard working man and he is generous and helpful.


This is all background info for the following scenario that went down on Saturday.
We went to dinner, him, my son and myself, we went to our favorite restaurant, the whole time, his phone kept beeping, he received maybe a dozen messages. He kept saying that "dave" wouldn't leave him alone. Some messages made him crack up. At one point my brother texted me and it was hilarious so I handed the phone to him so he could read it. At which point he showed me his screen that had "dave" and "nick" , his brother and friend, texting him.

Now to backtrack, he cheated on me for 8 weeks this past summer.
I was depressed as all hell, and in total disbelief. I moped around and was devastated to lose the man I so desired to spend my life with. He ended up asking me back, and I gladly accepted because I couldn't bare the way my heart felt ( yes, it sounds cheesy), and I did not want my future to be without him. That was May-July. During the time we were apart he was very callous and blunt when I would try to talk to him, saying things like "i might fuck her, I might not" ... I had a car accident where I was hit head on one night and went to his house afterwards for comfort and he turned me away because he was going to meet *her*

Here is the current situation. Saturday night I had him drop us off at my brother's house. Him and my brother were chatting behind the truck and I noticed "michele" pop up on the screen. I got this surge of anger and thought "I think not" ... Picked up his phone, saw all of the messages from "dave" .... talking about meeting up, how they missed each other, etc.
I immediately decided I was going to settle it then and there. I put her number in my phone and said hello, I mentioned that she was texting my boyfriend and asked if she would please just tell me if they are sexually intimate so that I could just move on if that's the case. This woman (and it is hard for me not to call her other names after the way she behaved) immediately knew who I was. She started calling me "trailer park trash" and said as if in recognition, that I'm the "beyotch" that he's just been using for sex, she said that he doesn't care about me at all and that he hates my child and that he gets in the way, she said that he told her that my child is a bastard and that his father wants nothing to do with him because of me. I will open up for the sake of the degree of how twisted my fiance seems to be and share that I am no longer with his father because he raped me in front of my child, though he was only an infant. This woman went on to say that my fiance calls me worthless because I don't even have a driver's license and because I live with my mother.

When I confronted him after he spoke with my brother, he claimed they dated 12 years ago and that she's only saying those things because she's jealous.
But failed to explain how she knows about me?

Now, I lived with my mother years ago after my initial divorce from my husband, I lived with her for 8 months while I got back on my feet.
I am just a bit shocked at all of this. My fiance and I were a normal couple with normal behavior and an extremely healthy and active sex life.
I never expected him to treat me this way, or talk that way about me, and he must have been spending time with this woman for some time now, because of the extent of details that he has told her about me.
I don't understand why the charade? Why marry me and spend time with me at all? I honestly don't feel that I put any pressure on him for anything, I was reluctant to move on to marriage because I wanted to spend more time together because of what happened in my first marriage but he ensured me that he cared about me and loved me and that those things would never happen with us.
What kind of individual does this to someone? Why?
Anything similar ever happen to you?
At this point I"m just pissed. I don't ever want to see him again. I don't want to speak to him.
But, I do have feelings left inside for my love that I had of us together, and the betrayal still lingers.
Edit:
To "MESSYKAT"
You can not base my parenting skills on one post. This post is not about my child, this post is about the opinion of people as to why this man would behave in such a way. If I was asking for advice on how to raise my child or what you think this will do to my child, I would have posted about that. Obviously I'm aware that this person is bad news for my kid and myself, if I didn't realize that, then I would just stay with him, but as I said, I am not staying with him. I've already left. Pay attention to the details and the question at hand before going off on a tangent about something you know nothing at all about.