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Phrase(s): tickled pink
Fig. very much pleased or entertained. • I was tickled pink to have you visit us. • We were tickled pink when your flowers arrived.
McGrawhill's American Idioms And Phrasal Verbs
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Also, tickled to death. Delighted, as in I was tickled pink when I got his autograph, or His parents were tickled to death when he decided to marry her. The first term, first recorded in 1922, alludes to one's face turning pink with laughter when one is being tickled. The variant, clearly a hyperbole, dates from about 1800.
American Heritage Idioms