As an educator, it seems like I am the 'camp magnet' for all the kids that are (pick one or many): social misfits, developmentally delayed/Aspergers/etc., only children, lonely, told to 'bug off' by the parent(s), the list goes on.
Sometimes I have to be rude/mean to them just so they'll leave.us.alone. I do NOT want another child tagging along on our hike/pool time/mini-golf trip/etc. I don't want the responsibility. I don't want my SON to be burdened down by a playmate he may or may not get along with. I don't want to be pestered by incessant questions, comments, or aimless patter. I also don't want to feel like I need to 'hide' in our RV all the time to 'escape' an uninvited guest.
I won't be 'rude' at first. But if the kid doesn't get the message, I will politely but firmly escort him back to his campsite, introduce myself to the parent(s), and say something like "I thought you might be wondering where Little Johnny has been since he's been at our campsite for XX hours. We're fixing to eat now so I thought I'd be sure he got home safely and you knew where he was."
Sometimes they even offer me a beer!!