Ich glaub mein Schwein pfeift

Literally: I think my pig is whistling

Example: “Sie hat mein Auto verkauft? Ich glaub mein Schwein pfeift!” — She sold my car? Well, I never!

English equivalent: Well, I never!

Origin: One theory traces the phrase to 1920s Berlin slang, tied to a specific kitchen object: round, potbellied water kettles fitted with a whistle on the spout, visually reminiscent of a piggy bank, that whistled loudly once the water inside came to a boil. Saying "I think my pig is whistling" supposedly gave someone an excuse to interrupt an unpleasant conversation and duck into the kitchen, before the phrase broadened into a general exclamation of surprise or disbelief. A second, simpler theory reaches for rural life more generally, with farmers who spent their days closely observing their animals reacting with genuine astonishment whenever livestock made an unusual or unexpected sound. The phrase is documented in wide use by the 1940s, which rules out a popular but false claim crediting the West German Sponti protest movement of the 1970s with inventing it — that movement, at most, helped an already-established expression spread further.