I caught Digger just as he was raising his leg on the couch, I yelled "Hey, get outside!", while stomping my feet. He ran out so fast he knocked Dozer over, which made Dozer think he was in trouble. I had to stop and pet Dozer, to let him know he wasn't in trouble. Digger kept sticking his head in the dog door, and I would say, "You just stay outside." He knew he was in trouble.