#double-crosser__double-dealer__two-timer__twotimer__betrayer__traitor  a person who says one thing and does another
  supertype:  #deceiver__cheat__cheater__trickster__beguiler__slicker  someone who leads you to believe something that is not true
  subtype:  #Judas  someone who betrays under the guise of friendship

No statement uses or specializes #double-crosser; click here to add one.