Vulnerability literally means exposure to possibility of being harmed. In relationship it refers to any form of putting yourself out there where the other person's response can be hurtful. We are vulnerable because we want to be seen and held. Sometimes we throw up defenses though to fend off possible rejection. This can sometimes look like a personal attack, such as "you can't handle me" or something along those lines. Anytime we share something sensitive and vulnerable and we don't open up to truly hear how the other person received us we are actually reducing our ability to be heard and seen and received.