The mlcer prefers the use of texts or emails because they don't have to hear our voices and possibly the pain in our voices. Keeping to texts or emails is another way of keeping track of what we have posted to them, and yes, they can use the written word against us in court to prove a point.
As for him not understanding what the money is for, that's BS. He's trying to get you to tell him what is in your separate account. If he wasn't prying, I don't know what is. He really does think you are hiding money from him and thinks you are making expenses up. At this point, since he's been a butt about this situation, I don't think I would tell him that your check isn't going to be going into the joint account in December. I think I would remain quiet on that until further notice.
I think you did well in calling him on his silly self, talking to you like a child and talking down to you....that's just the controller in him trying to intimidate you. You stood your ground and that's got his a bit confused because he doesn't know how to take back the control over you telling him things.
I agree, I don't think he liked the comment you made about making other arrangements. If he continues to be a butt, I would seek out the other arrangements and let's see how he feelings about the legal system questioning him about his accounts.
Keep up the good work. Protect yourself and your children.
Sit quietly, the answers will reveal themselves when you least expect them to. The past is gone, the present is a gift and you need to focus on today, allow the future to reveal itself when it is ready.