I totally agree with you, keep the kids away, they are the most important people here and what happens in front of them will stay with them forever! You know that you are doing the right thing for your family! As for FIL, he will probably be going through phases of wanting to play happy families when things are going well, even though he knows that it can change in an instant, he is in denial! They can always visit you if they want to see the children. Stand your ground!

Hugs xxx