Keeping Passion Alive in Long-Term Love

This is a great little article in Scientific American about the research being done on intimacy and desire with long-term couples.  This research indicates that when partners are well-attuned and emotionally-responsive, the feeling of being desired increases (as does sexual-arousal).  Ironically though, many couples report a decline in sexual arousal as the relationship becomes more comfortable (The Intimacy-Desire Paradox).  So what is happening there?  Why would emotional attunement, and/or our experience of being desired, decrease over time?  Here are my thoughts:  

I'm wondering about our experience of being "desired."  Perhaps some of the experience of being desired initially can only be correlated (subconsciously) with rather superficial aspects of self.  That person who sees us from afar doesn't really KNOW us.  Initially we are attracted to maybe humor, beauty, charm.  But what about when those qualities fade into the background of a real relationship?  When we are not at our best; when we are slogging through the day-to-day boring life tasks; what then is desirable?  As we live day-in and day-out with our partner, its generally not explosive passion that keeps us together.  Its those deeper, more subtle, values, qualities, and characteristics that keep us moving towards one-another.  This type of being known, is a wholly different type of intimacy. 

I wonder if this deeper intimacy is scary for us.  I wonder if its so intimidating and intense that we are reluctant to name this intimacy.  When I work with couples, and we get down to the deeper levels, I hear them say "I was so scared that I was too much for you.  I would overwhelm you if I was really myself."  "I was scared I would never be enough for you."  "I couldn't ask you if you still loved me because I was so terrified to find out that you didn't."  "I was scared that if I really let you in, you would find out that I was a fraud."  FEAR.  Like, heart-racing, crying, sweating, FEAR! 

I wonder if part of the reason that sexual-desire starts to drop off as intimacy increases, is because we quit sharing about how connected, amazed, dependent, comfortable, etc. we feel.  It might feel too scary at a certain point to keep going deeper into those conversations.  Essentially, as time/dependency/relationships go deeper, the risk goes up.  The fear of reaching and sharing deeply goes up.  We become reluctant to share about the heart-achingly beautiful connection we feel with our partner, because it would be SO vulnerable and emotional to do so.  So, we hold back and we simply say "Oh! I love you so much!" (that's if we are brave).  It would be too vulnerable and terrifying to share how deeply connected we feel/long to feel.  So the sense of being desired diminishes.  There goes sexual-arousal, and here comes confusion!