duplicitous

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
    

Related words

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