My own son who just turned 4 does this...I have never told him he has to ask permission and he has been trained for 2 years, so I think it is jsut a developmental thing. He doesn't wet himself or anything like that, but he always need to anounce to me that he is going to go...especially if it is poop...he will keep on shouting it out untilI respond and then he will go...and then when he's done he will shout out "I'm done!" until I respond and then he will finish up and wash his hands. I think maybe kids just feel more secure sometimes knowing that we know where they are and what they are doing.