Job is very very wise and has helped so many people here.
Please do not call your h out in front of the kids. During MLC we have to suspend ideas of what is right and normal social interaction at this time, and consider it from his point of view (hard I know when they are so crazy).
Try TED at a later point - 'tell me' 'Explain to me please' 'Describe'
It is OK to say calmly that you cannot accept this behaviour towards the children, and to ask him not to. Boundaries, firmly stated and enforced are helpful, but do not become the parent (he is rebelling against his mother right now).
Someone once said that in MLC we steer a fine line between b*tch and doormat. Because they are acting like a teenage jerk when they aren't being a spoilt toddler, it can be very hard to get through to them.
This behaviour exhausts our reserves of compassion. Only you will know how much you can take, but try and rise above it, and try not to be frightened of the rages. I was - some can laugh but they terrified me because they were so out of character.
