The immature behavior IS hard to take but the longer you ignore it the easier it gets. I so many times want to tell him that I have enough kids to take care of I don't need another to deal with.:) It all seems so silly - he can ignore my calls (though I pretty much never call him anymore) but if I do that or I am evasive about where I am going then he gets so irritated. The longer you can go without taking the bait, the easier it is.