it sounds almost as if you are trying to PROTECT him from any of the divorce consequences. you have relieved him of ANY responsibility and are still acting as if you are married.
your kids are 5 and 2. they won't remember if they went on this one camping trip. unless while at said campsite they drunken father goes into a rage, or the grandparents aren't watching closely and someone falls IN to the camp fire, or the lake, or wanders off. i think you need to dig deep - who are you REALLY doing this for?