No, but they know each other incredibly well, having been literally never left each other's side all their lives (they are in their early twenties). They will talk to each other when planning, but since each knows the other's fighting style so well they can generally predict what they will do. They avoid anouncing what they plan to do in combat for this reason, and that generally it's a bad idea to say "I'm going to stab him now" when trying to win a fight.