When I was much younger, I was a very jealous person. Had a unhealthy dose of hate going on' . some spite thrown in for good measure, and I ruled my relationships with a bit of a iron fist. ( No really, I was a total peach to date !
My wake-up call came when I realized, that all my jealousy, was always a direct reaction to other peoples' possessiveness over me.
When they laid down their mono-rules of expectation on me, I tended to inwardly panic. Some part of me wanted to hold them up to a even higher standard. Maybe my spiteful self, wanted them to share my panic.
I became a whole new person in that moment. Started being with people who understand that I own my body, and they own theirs.
I changed my behaviour almost instantaneously. With no one trying to restrict who I really was, I in turn, did not feel a need to restrict others.
I don`t ever feel a need to be #1 to anyone in my poly relationships. Almost to my detriment sometimes. My ex bf who had a wife, and live-in gf, could not understand that I was happy, and healthy being #3. I liked knowing my place in the pecking order, and had no wish to over-ride anyone else. I choose to let relationships evolve how they are meant to, without force or expectation.
My bf now , ( and come to think of it, also my husband,... ) have many admirers, and I tend to think; 'Good for him. He is a great person. He deserves the attention.'
It`s a great place to be, when you go from one extreme to another. The 'another' being a place of peace and understanding.
Marvel over it, but don`t worry to much.