Once when my oldest daughter was around 7 or 8 years old, she was pulling a drawer out of her chest of drawers and it accidentally fell completely out onto the floor. She said the D word. She was in her room by herself, but I was walking down the hall about that time, and heard her. I stuck my head in her room and said, "WHAT did you just say?" She repeated it and kept on working whatever she was doing. It was one of those times that you know it's wrong, but it's funny at the same time, but you try not to laugh because you can't encourage it!
We talked about that not too awfully long ago and she said, 'Well, you asked."