Nancy Wagaman Interpretation: Dreaming that someone has betrayed you or is a traitor can represent feeling suspicious of them in real life, exploring a worst-case scenario, or feeling paranoid in general.
Your loved one betraying you can represent: insecurity about your ability to hold their interest, or fear of them cheating on you; jealousy about your loved one paying attention to a pastime other than you (having nothing to do with actual cheating).
Someone other than a romantic partner betraying you can represent someone in your life you don’t trust or you feel has betrayed you (such as a person, yourself, or God).
See also: Interfering; Lied To, Being; Agreement, Breaking an; Dishonest; Trust; Telling on Someone; Sabotaged, Being; Abandonment; Catching Someone; Leaving a Person; Cheating; Trickery