When close friends have been together for a long time, they influence each other in an ever-expanding variety of ways. Those frequent replies appear numerous times. They react to events that are closely related to what is going on between them in the relationship from time to time. Something that happens between them at various occasions awakens memories from a previous period, which may or may not have anything to do with their current connection. Typically, it is a combination of the two.
When a present association triggers a past recollection, particularly one that is angry or awful, either assistant may believe that the emotion is about the person being referred to when it isn’t.