Luna says, "Who's this kid and do I need to listen to him too!?" The answer is "Absolutely!"
Tracy's son, Kenny, is letting Luna know that she needs to respect his authority, too. A few leash drills and circles are all it takes for Tracy's family to introduce themselves. She's learning to walk with a loose leash, at her handler's side, NOT dragging anyone down! Luna also needs to follow the rules no matter where she goes or who she's with. These exercises will also make her more respectful of personal space.
Structured games and interactions that incorporate leadership make it clear that kids are not litter mates. They are litter leaders!