From Longman Dictionary of Contemporary Englishthrow somebody a curvethrow somebody a curveAmerican EnglishASK A QUESTION to surprise someone with a question or problem that is difficult to deal with → curveball → curve
Examples from the Corpus
throw somebody a curve• The governor threw them a curve when he announced that funding would be cut.• The flushing models have thrown a curve to geophysicists trying to work out how this cycle has come about.• He expects to profit from the high strike mostly when he throws his overhand curve which breaks late into the strike zone.• Just when you thought you had it all figured out, it threw you a curve like this. 