Lucas & I both use my Facebook account and both of our emails. We always talk things over, are smart enough to tell if we have "liked" something, nerver post the same thing, never get mushy, usually sign our initial, and no one has a problem with it. They know us. For the emails, why would anyone say anything to one of us that the other can not know? If it is that personal, it certainly does not belong on the web. It should be face to face.
We have never been people to talk about way personal stuff to others, anyway. Everyone knows not to criticize either of us, and we never tell anyone about our little marital frustrations. If they share too much, they know both of us will know.