I wouldn't ASK him if he's away for four days I would move in while he's gone!
Don't ask.. dont' even tell him you are moving back in
After you have moved in tell him something like :
"I am moving back in for our children. I am mortified as it is that you are threatening divorce on the stability of this family, the last thing I want to do is have them house-hopping too. I dont' want to be here... It is pretty clear you had a woman here as well... But our children need a HOME even if you don't care, I DO."
I would also tell him that since he took the house and shipped the kids ELSEWHERE while he used the house just for HIMSELF that you cant trust him to use it as a responsible parent.
STill working on the second part on how to phrase it.
Notice I am steering everything in the context of parenting and child care/stability... if he argues with that it just exposes him as a bad father.. and in my opinion any man who hurts thier children's motehr is a bad father.
I woudl'nt wait to get his say so, I would move in while he's gone.. once his stuff is out of the house and yoru sis there he can't argue much.
And ya, learn patience... dont' give him ANY warning... it won't help your case.
