I can see both sides and I've found myself in a number of positions regarding this.
There really isn't anything I keep from Maca beyond what HE has asked me to not share with him. GG doesn't give a damn what I tell Maca.
There isn't really anything I keep from GG either.
On the other hand, there have been a number of things I've requested that Maca not share with others and there have been a few things that I've asked him not to share with me about others........
I think it works best when you can take each situation as it presents itself.
If you create a "rule" to abide by-and then something comes along that doesn't fit into the rule, you have to figure out what's more important, the rule or the problem that doesn't fit in it.
Whereas-if you go with the flow of things, communicating honestly and openly about the needs for privacy or lack thereof as you go along, you can deal with each thing appropriately as it arises.
There is very little I mind Maca or GG knowing about me and I know I can trust both of them with information about each other, because we're family. Same goes with Mimi.
However, if you aren't part of the family yet, well then as far as I'm concerned, there's a whole lot of info that isn't yours to know....
"Love As Thou Wilt"