Of course there has to be one.
We share a back field with the neighbours on either side, both of whom have children. They all play together (including a preteen boy who is very fond of playing with the FB which does feel a bit weird) in the back field but also in our back yard which is meant to be private. Now it is fine that they all are in there when the FB is out, but they've taken to using it as a shortcut when he isn't there, and being an intensely private person I'm not happy about that. There is also a problem with one of the children who has taken an immediate dislike to the FB (not enough of a dislike for him not to come round and play with all the FB's toys), calling him names and trying to isolate the FB from the other children. I don't know how to handle all this. I don't want to appear standoffish and therefore cause problems for the FB but I also don't want my backyard to become their playground and I certainly don't want the name calling etc to continue.