What did you do when he was peeing in front of you? What about training...have you started working on obiedience yet? He needs to learn the word no and you should put him outside or out of sight while you clean up. You don't want him to think that it is ok. No need for hollering just a stern no. He is still pretty young and could have just had a lapse or maybe he really had to go and if you were not paying attention to him notifing you, he made you pay attention. When they are young they really do not the control that older dogs have. If he continues I would take a trip back to the vet. A lot can change in a week and he could have an infection.