double-dealing

Adjective

• marked by deliberate deceptiveness especially by pretending one set of feelings and acting under the influence of another
  • she was a deceitful scheming little thing- Israel Zangwill
    
  • a double-dealing double agent
    
  • a double-faced infernal traitor and schemer- W.M.Thackeray
    

Noun

• acting in bad faith; deception by pretending to entertain one set of intentions while acting under the influence of another

Related words

• Synonyms: 
  ambidextrous , deceitful , duplicitous , Janus-faced , two-faced , double-faced , double-tongued , duplicity