Yes, the original plans were made to include everyone, not a "tag along" type thing. A actually invited D directly.<quoted text>
My first thought is that you made plans with D based on something that A invited you to. You did not make plans with A and invite D along, right? If A changes her invite then you, as the couple who was originally invited, are free to decline.
However, if B is only going to be there for the weekend and throwing a big get-together is too much for A to manage, then you have a couple of other options. You can throw something at your place that includes D and everyone else on the original invite list, or you can just talk to D about the change of plans (it's not like this was a formal party with engraved invites that were sent up - it sounds like it was half a step up from an impromptu get together). I can't imagine that he wouldn't be understanding and supportive of your desire to hang out with two girlfriends, one of whom you rarely see.
B is going to be in town until June 3rd or 4th, I don't remember. A and I talked about the three of us doing a beach day this Sunday (Memorial Day weekend) and also getting together next weekend, so I'll definitely see B anyway.
I'm not going to host something myself because the other people, with the exception of C, are A's friends, not mine. And one of them (her neighbor) I've never even met.
I'm sure D would totally understand and I know that guys are way different about this kind of stuff than girls. I'm just annoyed that A's rudeness is putting ME in a position where I have to be rude too. And I'm surprised that she just assumes that I'm still going vs. leaving it open either way since she changed the plans.
Ugh, not looking forward to either conversation. I feel like I have to be the mediator, and almost like I have to make excuses for A since D has only met her once and I don't want him to think less of her because of this.