Some people may prefer the label to help them better understand what kind of relationship they share with each other. There are others who choose to shed all labels and honor the relationship as for what it is, and not restrict it to any label. It completely depends upon the partners to be honest. If they feel that a label might help them understand the boundaries and set correct expectations, that is totally fine. On the other hand, if the partners feel that they need no label to define their relationship – it is the connection that matters most for them, it is equally justified if they do label their relationship.