Boundaries - when someone you share a lot of stuff with, knows a lot about you if not almost everything goes ahead to follow you everywhere and it s not that you don't like it, but the people around get to know a lot about you too. Things you don't like to share at all. Like who you are in your
private life, who you love, who would you like to fuck, who makes you horny and how or
why and all other stuff that should remain rather private, doesn't matter if I don't care about their opinions or not. I think that there are some things who should remain strictly between partners. Especially if you are quite private with your life and don't like talking about yourself with almost anyone.
Opening up with someone shouldn't give them the right to open these to everyone else.