To be completely honest I see no reason to talk with them at all. As soon as they say "hey spotlight" and you realize they aren't bringing you a beer I'd tell the family to get in the camper and head for the camper myself. Lock it to observe from inside. If they do anything destructive to your stuff then call the police.
I would not even say "I don't want any trouble." Who in the hell ever responds "Oh OK, we thought you were, sorry for the confusion." and then they turn and walk away.
I agree with GTG as I typically do. Once inside the camper if they attempt to enter and make it inside shoot until the threat ceases (read slide lock).
But wheres the Bravado in that kind of reasonable thinking/acting?
J.K.