Got to agree with AF here.
I know you so want him to face up to it, time to realise he won't he is a cowardly shit.
It's so sad but like someone else said up thread, it's time to realise, it's not what you want him to see, or what you think he needs, it's about the Dc's now.
You asked what can you do to help? Tell them the truth, tell them why their Dad has left, why he is not at home, why he is acting how he is, why you have been how you are.
It will be awful, but then you can mend, the horrible cloud of uncertanity will be a living hell for them, they know something is up, but don't know what. I do think they need to be told and I don't agree with the poster who says 2 days won't make a difference.
It will to a child that is feeling this level of anxiety and uncertantity, it will be awful.
I think we all know he will do his best come Weds to get out of it.
He really is a nasty piece of work, who does not care he is emotionally damaging his dc's like this.
This man is sacrificing his childrens emotional and mental wellbeing, to save his own skin. As he can't face up to his actions as he is a coward. He'd rather they continued to suffer in the dark for a few days more.
Read that paragraph back and realise how utterly disgusting he is.
The children now they are at this stage, may start to get angry the more it's kept from them too.
Wish you well whatever you decide.