This is a really messy situation. If he is visiting at the house that the wife lives in, then that just isn't good. He can bring his child over to your house, or where ever the two of you live. If it was me, I would remove myself from the drama. Tell him this is how it's going to be. If he chooses to stay with the wife, then I would give child support a call. It's really not healthy for the kids to be put threw this mess. You need to look out for you and your child.