look up and look who it is.....now what?!

Last week I got a text out of no where the message was just my name and when I looked at it I didn't immediately recognize the number so I said "yes? and this is??"  They responded with their name and a host of memories, thoughts and somewhat nervousness came over me.  You see it was the ex no not him but the ex from before the father, the same ex I left to be with the father.  The same ex that the father have always felt insecure about yes the same ex I never really stop caring about.  Why was he texting me? What do he want?
I responded back and we talked/texted you know the usual, how are you? how is everything? what are you up to?  Yes the "how is the weather conversation", after a few messages back and forth I asked him what do you want?  He didn't know, he said he just decided to contact me after thinking about me for sometime.  I said ok and I was cool with that. 
For me r-ex(which is was he will be referred to) brings alot of different emotions and kinda turns me all icky.  I hate that and that's why I would rather not be in regular contact.  We where in a 5 year relationship which had its highs and lows.  See when I met r-ex I was young and he taught me the kind of relationship I wanted and didn't want to be in.  While he had great qualities and I loved him tremendously he was a cheater and after break up and heartache break up and heartache I decided I needed and wanted better.  I was at the end of my rope with him when I started my current job and thus met the father.  That is the very short version.
We have been exchanging messages daily and while I like talking to him because I don't hate him or anything like that, I really don't find it necessary.  What I mean is no he is not going to be my friend because as I stated in a previous post ex's are not friends.  I do think of him time to time but my life has gone in a direction and I am pretty happy with.  I feel we both have had moments of "what if" but I don't dwell on that.  He wants to met up and talk I said I would, I'm not sure what could be said but I"m willing to talk.