A few months ago, DS (14) got into the habit of going off on one if anyone used the bathroom when he needed it. When people are on toilet, he screams abuse at the bathroom, thumps the door, kicks it, shouts disgusting songs and passes obscene notes under the door until the person hurries up and finishes.
It just used to be with us (the family) but now he does it to anyone. My poor mum was in there at the weekend and almost fell off the toilet when he started screaming and banging and then this morning, the plumber was in there and DS shouted "wanker, get out of my bathroom now!" through the door. The plumber was fuming.
How would you handle this?