So… I live in a neighborhood with a lot of young, fun couples/families and on weekends a handful of us like to get together at one of our houses to make dinner and play games.  In the last couple of months we have some new neighbors that moved in directly across the street from me, and despite the fact that they've never been invited to the dinners and game nights, they will just randomly show up.  They don't even knock… they just walk right in, say hello to everyone and make themselves comfortable.  They eat our food, they drink our booze… and because of them, people who have been invited now have to stand around the table playing games because there aren't enough chairs.  It's always awkward and uncomfortable for those of us who have been getting together for years, because we all know this couple is crashing the party.  So my question is obvious… how does one kindly and respectfully say "Don't come over unless I invite you!" without totally sounding like a b*tch?  I mean, they're my neighbors and I'm stuck with them so I don't want there to be any bad blood, but summertime is coming up and I have a pool, and I swear if they just randomly show up in their bikini and swim trunks with their kids one afternoon I'm going to seriously lose it.

Oh this made me laugh so much.  I’m sorry, I know that doesn’t help.  But Holy F-ck, how do people like this exist?!?  
Okay, here’s what you need to do.  First things first, lock your goddamn doors. (p.s. where do you live that you’re not doing this in the first place?!) Here’s hoping the physical block from entry into your home will serve as a clue for them to f-ck off, but by the sounds of it, these people are too socially geeked out to get the hint.  So chances are they’ll probably start knocking.  
Ugh, I’m cringing already.  
If that’s the case then you’ve gotta be honest.  Look, if these two have the balls to waltz on into your house like it ain’t no thang, then you absolutely have the right to be straight up with them.  Just tell them that while it’s nice to see them, you’re having a private get-together and it’s not a good time for them to come over.  
AKA. Kick Rocks.   
I mean, that’s really all you can do without coming off like a giant asshole.  Hopefully they’ll get the point, but sh-t, if you need to continue telling them the same thing over and over each time they pull a social home invasion, so be it.   I know that doesn’t sound “neighborly” but who are we kidding, what they’re doing isn’t either.  
Now, with all of that settled, when can I use that pool of yours?