Do you think there's a dark side in every marriage?

I'm not sure about every marriage but I'm sure some do. I don't feel like or believe that there is in mine...we keep everything out in the open with each other and though we don't necessarily lay open our marriage to others nor do we actually hide anything either, we do choose not to reveal or discuss certain things (but would if necessity calls for it). there is nothing that either of us is or should be ashamed of.