It opens your chest and it opens your heart and it means someone can get inside you and mess you up. You build up all these defenses. You give them a piece of you. They don't ask for it. They do something dumb one day like kiss you, or smile at you, and then your life isn't your own anymore.
Love takes hostages.
It gets inside you. It eats you out and leaves you crying in the darkness, so a simple phrase like 'maybe we should just be friends' or 'how very perceptive' turns into a glass splinter working its way into your heart. Not just in the imagination. Not just in the mind. She will wash and cook and clean for you, she will listen to what you have to say and never interrupt you.