绿帽子到底羞红谁的脸
[lǜ mào zi dào dĭ xiū hóng shéi de liăn]
Literal meaning is 'Green Hat Ultimately Blushes Whose Face Red'. A metaphorical expression about cheating, 'green hat' symbolizes infidelity, and blushing suggests embarrassment or shame felt by people impacted by it—either oneself or another person caught in a compromising situation.