I am not yet divorced so I am not in this stage yet. I would think once the lawyers/courts are involved you want to be straight up. I would think its hard enough without having to remind him its his weekend, plus I would think having a lawyer do all your reminding would cost you more $. So I would send him an email documenting that it is his weekend and if he does not respond than you will be taking the responsibility of having the kids for the weekend. That way you are covered and the facts will not spin out of control. Keep the email short and factual. Hope that helps.