Plan your own vacations when you want to, and plan a suitable combined vacation with this other family when you want to. If they freak out at your planning your own vacations as you see fit, then let them. Bowing to unreasonable demands because someone will make you pay emotionally if you don't is not a healthy option.

Unfortunately, I think the expectation is that birthday girls don't pay.

I think we'd all hate to be the one who gets declared undateable by one's entire grad-school population based on a couple of told and retold stories.

It takes awareness that it's not only not a bad thing to let others do things their own way, it is in fact an improvement. It makes life richer and more interesting.

Awkwardness is when there's a risk of a perception gap between what you mean and what you appear to mean.

If you are being shuffled around, then you should feel shuffled around.

Of course the thoughts and awareness are there, but it's all incomplete and often fanciful - kids know there's something to know, and they fill in a bunch of the blanks with their imaginations if their parents haven't had the conversations and/or established themselves as sources of information. It's rare that the kids know nothing at all, and the somethings they do know are often only partially right or flat-out wrong.