Have we got this one already?

One character tells another something that sounds flattering or nice, which makes them intrigued, only to have the complimenting party flat-out insult them instead. A form of Comedic Sociopathy. Super Trope of NOT. Compare Stealth Insult.

Examples:

• From Futurama's spoof of The Wizard Of Oz:
  Amy: (as the good witch) Ooh! Those are great shoes!
  Leela: Oh, thank you.
  Amy: Do they come in women's sizes?
  (Leela presses a button on her wrist machine and the steps come out of the ship and crush Amy.)
• A Catch Phrase of Triumph the Insult Comic Dog is, "great [x]... for me to poop on!" (Where x typically refers to some sort of noun.)
• In Tangled:
  Thug: Go. Live your dream.
  Flynn: I will.
  Thug: Your dream stinks; I was talking to her.
• The George Lopez Show: A cosmetics sales representative advises Angie to use these to make her customers feel self-conscious and buy makeup (e.g. complementing someone's work ethic because of the bags under their eyes).