don't get it! Help!

[kissak]

It's not that I really call him to fuss, it is during times he calls me and asks me how I feel about something and I tell him the truth about it and I say Im sorry, that's just the way I feel and he always says, "I understand". Like yesterday he new I had went to the doctor for something and I hadn't yet told him why, He called and made it seem like he wanted to know about the kids and how they were doing. He never does that. I asked him was that all he wanted, He said, "kinda sorta not really" (his favorite saying by the way) I should have left it alone, but I said what do you mean not really, He asked what I went to doctor for. I told him I didn't want to talk about it. But he kept pressuring me to tell him. He was genuinely concerned about me I know. He asked why couldn't I tell him. I said, because you are not there for me to talk to anymore about things that go on in my life. I hurt me to say that, and he says, "I understand". I said, but you don't understand, I Can't talk to you about things anymore. He seemed so concerned. I know he still cares about me and it hurts that he only wants to be friends through this. But I will try to be a good friend to me so when this other woman hurts him , maybe he will come to me for comfort. I don't know. I don't really call and fuss at him, I should have worded that different. Now I need to bring up the subject about when our children visit everyother weekend I don't want OW there at his apartment. This is visitation time for him with his kids, Not for her to visit with his kids. How do I bring that up without conflict and pushing him away. It's only for the best interest for our children. They are only 6 and 10.