Every time they do it....wash their mouths out with soap...Keep telling them what you are going to do, and act on it.
I don't have kids...but there are enough of them around that act out of line all the time...stuff my parents would have killed me for.
I recently almost put the "smack down" in such a white trash wwf way on a 10 year old girl that stood up out of her chair and screamed at my husband. Completely out of line...little shit.
That's exactly what I said, since
no adults around said anything to her. They just sat there looking stupid....
at our house eating our food.
"Hey Kid, don't be ruuude!"
She got one of my hell looks. The kind of look that stops time. She found herself in a daze rather quickly...I can be pretty mean looking.
Think of it this way, you should do something about it before someone like me comes along.......