This is an issue we've actually discussed and probably doesn't need to extend further than need be, but I believe we still haven't found a definitive solution.
Mahea, Evan, Stuart and I have an annoying neighbor kid who doesn't quite understand that he's not part of our group of friends, just an acquaintance with whom we are cordial. I treat him as nicely as I can, but he's not encouraging it by infringing upon every opportunity to tag along. Even Vince has experienced this. I tell him I'm working (which actually isn't a lie) but the truth is I can work in the presence of others quite easily. Just not people who will stare over my shoulder and will break my concentration by asking questions about what I'm doing - and then offering comments and anecdotes that do not elicit the slightest interest in me.
I'm really annoyed with this kid and I don't know how to keep him from pouncing on me every chance he gets. Subtlety obviously doesn't work. Maybe we should use more erudite language around him so he gets lost and can't participate? I dunno. Something. Anything. Help.