"No." Then he pulls down his pants and pees on the floor.
Now, he has been pretty well potty trained since this Spring so I can only think this is some kind of power thing. He stopped mid-stream when I yelled "What are you doing?" So I know its not a control issue.
I'm a pretty permissive parent and when I punish I like to make the punishment "fit the crime". ie, if he doesnt throw out his freeze pop wrapper he doesnt get another one or if he doesnt clean up his bath toys he doesnt get to play with them the next time he takes a bath. I have no idea what to do in this case.
It seems lately he is more interested in being more in control of things like picking out his own clothes and wanting to decide what to have for lunch, which I encourage, but this is crazy.