This is a long shot given how specific it is, but I figured I'd ask anyway :)
I would like to restrict posts, or ideally, part of posts to certain users.. without those without permission knowing about there was anything there in the first place.
As a fictional example, I might want to write about that birthday party where my friends decided to a stripper in a cake. Well, awesome as it might be, so much that I'd like to write about it, and share with close friends, I might be a bit uneasy about my parents reading about that. So ideally, I'd like to give my trusted friends access to that *post, and for the post to be completely invisible to anyone else. No "Enter password for more" message or anything like that.
Even better, would be if the system could protect part of a post, rather than the entire post. This would be beneficial for flow purpose.
For instance, a post may be structured as such:
a) Best friend ask if I want to get a quick lunch /public
b) On arrival I found that all my friends are present /public
c) Stripper cake /private
d) Of to karaoke /public
Ideally, the page would generated for those without access would be a), b), d) without a hint that c) even exist. Whereas those with the access would not need to click on a new link.
I've only just started using WordPress, but I am pretty sure that there is no such flexibility out of the box. The question is whether there's a plug-in / combination of plug-in that does all/most of that.