The kids at the campsite was driving me crazy!!

My friends don't know how to control there kids at the campsite. One of the kids was just walking away from us when we were walking around the campsite. She almost got lost. I was surprised they couldn't control there kids. The little girl has a foul mouth. The mother was telling her stop that . She would say i do what I want. She even slap her mother in the face. I couldn't believe it with my own eyes. My friend didn't even do anything. She didn't even tell her that's wrong. She said nothing. I was shock! They were driving me crazy constant screaming i want this and if they wouldn't get what they wanted. They were throwing things around. It's the parents fault if the kids are bad. I saw that over the weekend. It will be the last time I'm going anywhere with them if they have there kids with them.