because, Vancouver? Gotta keep your friends insecure to combat your own sense of worthlessness babe. A city without community where everyone is inundated with the idea they aren't as rich, smart or cultured as their neighbors.

oh my god, you've just described many interactions I've had with friends since moving to Van: "...yeah, and then tomorrow we're heading out to the park with some friends to chill. Bye now!" lol
I don't think it's your fault. It's cliquey as hell, and honestly it feels like people are kind of too tired to connect a new person into a group. It's like a chore. I don't know what's up, but good luck OP!

Because Sally isn't within that person's work circle. I doubt their coworkers were inviting anyone outside of their work circle either. We have our family circles, we have our close friend circles, and we have our work circles. Sally shouldn't have to feel the need to integrate herself into every aspect and circle of some other person's life. Not even family does that. But I'm sure Sally will have plenty of opportunity at the beach with Lisa within their close friend circles, and perhaps some of Lisa's or Sally's coworkers will have the honor off getting promoted to the close friend circle.

1) That whole not mixing of different friends thing. Lisa's friends from work don't know Sally, so they might not like an "outsider" joining them (though they'd be kinda immature if that's true)
2) Lisa's gonna see Sally again tomorrow at the birthday party, so too much Sally- no good.
3) Lisa is exercising her passive aggressiveness and/or power over Sally by not inviting her. Perhaps she was also turned off by Sally's desperation
4). Lisa's just a cold beeotch
5) Sally has b.o.

Instead of desperately hoping for an invite for an evening out with Lisa and the girls, Sally should be going out to dinner with me instead. I sent her flowers and a card to her office, and messaged her hinting about tonight's dinner plans. I guess she was too busy chatting with her friend Lisa to get back to me, so I totally understand her delay in responding. I shall remain hopeful and will catch up on some work in the office on this sunny Friday afternoon while I patiently wait with great anticipation for her reply.

It sounds like it was a "work bonding" thing....I have best friends that do all kinds of other social shit that I have no urge to be invited to.

I guess your answer just proves OP's point! I bet Sally and Lisa, and her coworkers are in a similar age range with similar interests. It's simply 4 women hanging out at the beach. Really not that complicated for christ sake! No one is stepping out of bounds here.
By the way, "promoted"? "honor" WTF? What cold terms to use.
These tiny little circles of "friends" are kinda sad when you think about it.
My idea of "circle of friends" is that it's a big one and some people happen to be closer to the center (you) than others, and NOT that you live across isolated (sad) little circles. Sally, all the best to you!

Your rationale pretty much supports the theory that Van is a hard place to make friends and to break in to pre-existing cliquey social circles.

Of what guys have to put up with. No wonder so many give up.

You don't break into an aspect of some other person's life to get to know everyone they know. It's not their job to be your social coordinator. Go join a club, or set up an activity with your own coworkers, feel free to go have a life of your own instead of being possessive of the life of another. Don't be a psycho.