Hi Painter, how did this work out?
When my ex used to want to see his son (before he got re-arrested), I would just say, call me when you are on your way over... and he never showed.
I never told his son that daddy was coming until he actually knocked on the door so that he would not be disappointed.
I'm glad he never showed. Cards from jail are better. Especially if the kids can't read so you can decide what the card says. My son occassionally gets a card from his dad. I read it to him. It always says, "I love you very much and I am sorry I cannot be there right now. I will see you when I can. Be good and listen to your mommy." No matter what kind of hogwash is actually written on the paper (usually it's just promises that most likely will be broken once he gets out)...