原谅我人好嘴不甜
[yuán liàng wŏ rén hăo zuĭ bù tián]
This indicates a candid personality. While the person is inherently kind, they may speak bluntly rather than sweet-talking. Translating directly: 'forgive me for not speaking kindly despite my good nature.' It reveals modesty along with frankness without hiding one's warmth underneath sharp words.