If they don't end up together, that relationship is not fate, and it's fated to be something else. So, that can't be 'the red string of fate'.Destiny, sometimes referred to as fate (from Latin fatum "decree, prediction, destiny, fate"), is a predetermined course of events. Predeterminism is the philosophy that all events of history, past, present and future, have been already decided or are already known (by God, fate, or some other force), including human actions.