@mistybby,
A long time ago a friend who was into the open marriage thing tried to convince me to join in the fun. He threw all the logical arguments at me. He asked me if fear was what caused me to shy away from extramarital sex. He asked if I was afraid that my wife would enjoy another man more than she enjoyed me. He even equated my reluctance to share my wife's sexuality with others with an ownership complex. In the end, I determined that it wasn't for me. I told him that it was something that just didn't fit into my life objectives. He suggested that I was just a victim of social convention and tradition, and that I was actually afraid of being compared to others. Then he said that if the security of my relationship with my wife rests on whether or not she has sex with someone else, then it was doomed from the start.
Many years later when I was able to think more clearly about life, I went at him like he went at me. I suggested to him that his desire to have an open marriage was a manifestation of his inability to find more depth in his relationship with his wife. I told him that his desire to have sexual relations with other women was his way of declaring that he had reached the depth of intimacy with his wife, and so, with no where to go from there, he decided to start from the beginning again, restarting the process of sexual discovery so that he could experience that initial excitement over and over again. He fell back on the old tried and true phrase: familiarity breeds boredom. I told him that boredom has nothing to do with what you are familiar with, but rather with how you perceive what you are familiar with. We ended our conversation with me saying that many shallow wadings does not a deep dive make.
This is just my opinion which is based on my experience. It is not a judgement. I might have it all wrong. Perhaps it is natural to have it all, but it just doesn't feel that way for me.