I was wondering what the hell was going on when I saw your posts on FB.
That just sucks. What a sick twisted situation you find yourself in. I know you said you feel badly for this guy but I agree you need to protect your children. If he is that OCD about tracking your STBX and OWs phone records, he is a meticulous, plotting SOB. So it is good to be careful.
So glad you are taking actions. If stbx doesn't like it, tough. You are a mom looking out for her kids.
And the whole lying thing in re. to OW is oh so familiar. Why lie if you want(ed) out? You guys are divorced, right? So what does it hurt him to just own up to it now? I will never understand these men....