Its a shame we can't just stick to the question in hand here instead of all this bickering! Bob, maybe you should be patient but firm, keep reassuring your girlfriend, and see if ex pulls back a bit. Whilst it is important to put your girlfriend first, it is also important that she sees the dilemma you are in re the kids. If she can't see it then she may also not be the right one (sorry if that sounds tactless - just my thoughts). New partners have to deal with all sorts of crap, and her heart has to be in it too, unfortunately. Take it from someone who has been there. Make sure your kids really know you love them. Make sure you tell them. My stepson saw the light in the end and knows which is the decent parent and step parent.