Definitions:

1. Pretending to act in one way while actually behaving in another, usually to deceive or manipulate others. NOUN
   • She ended her friendship with Sarah after discovering her double dealing, pretending to be loyal while spreading rumors behind her back.
2. Refers to the act of being deceitful or dishonest by secretly engaging in contradictory or conflicting actions, often with the intention of achieving personal gain or advantage. NOUN
   • The politician was exposed for his double dealing, promising one thing to his constituents while secretly working against their interests.

Synonyms:

• betrayal
• double-crossing
• duplicity
• faithlessness
• treachery