I guess this is different for everyone.
My wife and I make it clear to everyone we relate to that anything known to one of us can be known to both, meaning we can know all the details of our other relationships, but as we've gotten more used to dating other people we haven't felt as much of a need to hear every detail (it would be too time consuming), even though we still can. It's not something we do out of distrust, more that we simply like knowing what we're each experiencing.
We are very "couple-centric", and don't want that to change. There are things the two of us will only share with each other. Anyone that dates us needs to be ok with that. If someone just liked one of us and didn't really want to know the other, that would be the end of the new relationship. As a result, anyone we do end up dating tends to get along well with both of us and we all hang out together fairly often, including for holidays.