Platonic Friendship?
A nonphysical friendship can develop into an emotional affair when the investment of intimate information crosses the boundaries set by the married couple. An emotional affair is opening a door that should remain closed. One of the differences between a platonic friendship and an emotional affair is that emotional affairs are kept secret.
A third difference is that people involved in an emotional affair often feel a intimate attraction for one another. Sometimes the intimate attraction is acknowledged and sometimes it isn’t. Much of the pain and hurt from an emotional affair is due to the deception, lies, and feelings of being betrayed.