Even without talking and sharing, you both continue your lives, are growing and changing. You each are having new experiences, are having new thoughts, see things differently, and are becoming different people. If this continues long enough, neither of you knows the other anymore.
What about your relationship? There is no relationship to be concerned about. You may still be going through the motions; but what you had together is gone. Perhaps you can have a renewed relationship eventually; but not any time soon. You would have to start building it all over again, if there is any interest or motivation for that sort of thing.
Simon’s advice is simple. Talk and Share. Do it for each other, do it for today. Also do it for tomorrow, unless you just like starting things over again. Whatever your choice, understand the cost of your silence.