Mrs. H, I am so sorry you have to deal w/ such abuse...and that is exactly what it is. Not to keep comparing your sitch to mine; but, it is written in our custody papers that exH and I are NOT to speak negatively of the other in front of the children, nor are we to allow anyone else to do so. Luckily, my children are old enough that I do not have to say anything to them, they see for themselves. It seems that your sons do, too.
There HAS to be SOMETHING that can be done to put a stop to all of his horrendous behaviors! I feel so bad that you and your sons are having to put up w/ his crap. What an a$$!!
Please check into this. Be sure to keep a journal of all the things he says and does, even his showing up when it's your time w/ the children. Document, Document, Document. You never know when you may need it!
I do so hope that the rest of the weekend is peaceful for you and the boys!