嘴在逞强心在投降
[zuĭ zài chĕng qiáng xīn zài tóu jiàng]
Translates to 'The mouth talks tough but the heart surrenders', portraying a situation where outwardly someone appears strong or stubborn but internally they are giving in or have softer emotions beneath their bravado. It conveys a sense of internal conflict and vulnerability hidden behind a tough front.