你有一张不锈钢的嘴你有一颗棉花糖的心
[nĭ yŏu yī zhāng bù xiù gāng de zuĭ nĭ yŏu yī kē mián huā táng de xīn]
Describes someone with a 'stainless steel mouth' (meaning they speak frankly) but a 'candy floss heart', signifying sweetness, kindness, and gentleness beneath their words. There's honesty coupled with warm-hearted intentions behind potentially sharp comments.