Many, many people feel special in a relationship because of the things their partners do. For example, some people feel special by exclusivity--"I am special because he does not love anyone else," "I am special because he only does thus-and-such with me."
The danger in doing this is that if you're not careful, sometimes what happens is you end up placing your sense of worth, your sense of value, and your sense of "specialness" on things outside of yourself.
If you need certain exclusive things in order to feel secure with your lover and in order to feel unique and special and valued, then you will never really be secure and you will never really feel unique and special and
valued--because you will always know that these things can be taken away from you.
I feel secure in my relationships because I know, deep down in my heart, that nobody else is like me and nobody can ever take my place. If my partner Shelly does everything with her other boyfriend that she does with me--if she goes to the same restaurants, watches the same movies, has sex in the same positions--it does not bother me and does not make me feel jealous or insecure, because I know that the things that make me special and irreplaceable are inside myself, not outside.
My specialness does not come from the exclusive things we do. My specialness comes from *who I am.* Knowing that makes me secure, and it also means I don't need tokens of my specialness, like exclusive things from my partners; my specialness is assured, is concrete, and can never be taken away.
It's been my observation that the more you place your sense of value and worth on things outside yourself--the more you need, and rely on, tokens of exclusivity in order to feel special--the more you will struggle with jealousy and insecurity. Real security, in the end, can come only from within.
I think that many problems people have with their partners' behavior, especially in polyamorous relationships (but sometimes in monogamous relationships as well), come from the need to have their partner make them feel special. If you are in fact special to your partner, then there should be no need to set boundaries or controls on your partner's behavior in order to feel it; it will shine through in everything your partner does, all the time. If, on the other hand, you are not special to your partner, then controlling your partner's behavior isn't going to make you special.