I don't know how to handle this.
A month or so ago 8 year old ds told his five year old sister to fuck off. He got all privileges (DS or other gadgets, sweets or pudding) removed for a week.
Yesterday he was playing on his DS and shouted out "argh, you fucker" to one of the characters on screen.
I'm ashamed that my parenting is clearly not working and that he uses this kind of language.
What can I do to stop it?