Tā zǒngshì chuīmáo-qiúcī, méi rén yuànyì hé tā gòngshì.
He's always nitpicking - nobody wants to work with him.
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Literally: blow apart fur (吹毛) to look for flaws (求疵). Imagine blowing on an animal's coat to expose the tiniest blemish - that's how absurdly thorough a nitpicker is.
