Why Narcissists Believe They Own You
It's not uncommon for people in relationships with narcissists to feel as though the narcissist in their lives thinks they own them. They may take your things without asking, speak for you, insist on a detailed accounting of everything you've done, require permission for things and any number of other controlling, possessive behaviors.
This is largely due to the fact that narcissists cannot separate themselves from the world around them. Everything is seen as a part of themselves, like how very small children see things. If they see something they want, they just take it. It's a very simplistic and immature view. This is why no matter how many times you will say, "This is mine, please ask me before you use it or take it," they won't. Why should they have to ask? Everything they see belongs to them. This includes you.
It's kind of like the way you see your arms and legs. They are yours, you use them. You don't think overly much about them. Narcissists take for granted that what they want is theirs and always will be. This is one reason rejection hits them so hard. It disrupts that way of thinking. It shoots holes in that belief, and they react very negatively to it. If a toddler takes a candy bar from the shelf and tries to leave the store with it, you stop them. When you do that, they start crying because they want it and they don't understand why they can't have it. Narcissists basically react the same way. It's a reaction of loss and rage created by the inability to understand that not everything belongs to them.
Part of the reason for this feeling of ownership also comes from enmeshment. Narcissists enmesh themselves with people. It's the only way they know how to bond. Enmeshment is when the boundaries between two people are so poor that it becomes difficult for people to tell where their individual self begins and the other person ends. This results in the narcissist taking over the other person, asserting their needs in place of the other person's needs and trying to steal their personality and good qualities, like invasion of the body snatchers. When this happens, it increases the feeling of possession and ownership the narcissist has over the other person. And why wouldn't it? They've essentially taken over everything but the person's physical body. Some of the more overt narcissists even try to do that, creating rules and protocols for how the other person is supposed to talk, think, dress and behave.
It is for these reasons that narcissists can become very distressed at autonomous action or individuality by people they believe they own. That's not in the script. The people around narcissists are not supposed to do things that the narcissist does not agree with or is not involved in. If they do, the narcissist often takes it as a threat and a rejection, endeavoring to destroy this individuality completely. People might say, "Well, how can it be a threat or a rejection if it has nothing to do with the narcissist?" That's the threat. That's why it's a rejection: because it has nothing to do with them, or because they were not consulted or whatever.
Pathologically narcissistic people live in a world that revolves around them. Everything and everyone exists for them. They feel no hesitation about taking things, using things or people because they feel it is their right to do so, and no amount of explaining will make them understand that it's not OK. You can tell them over and over again and it won't make a bit of difference. Do yourself a favor: save your breath.