We dream of disappointment and anger when we have been let down in life or our trust has been betrayed in some way.
If you dream of your partner committing adultery explore your own feelings of vulnerability and insecurity. In dreams we project onto other characters our own issues so if this dream theme occurs ask yourself “where am I betraying myself and ignoring my own needs?”... The Premier in Dream Dictionary
(Deception; Double-cross; Milk; Misleading; Renegade; Trickery; War) In a dream, betrayal of others mean shortcomings or religious disdain and failure in one’s life in this world. Betrayal in a dream also means a robbery or being in dire need of the victim.... Islamic Dream Interpretation
All dreams of betrayal should be studied closely in connection with the entire dream to find out just who or what to expect betrayal from. Betrayal as an omen is not much to go on and the dreamer must take this as a literal warning of an insincere friend or lover and study the dream with this in mind. Sometimes things can ‘betray’ you by not giving you value and satisfaction for cost.... Encyclopedia of Dreams