【闻雷失箸】〖wén léi sh zhù〗[drop one's chopsticks on hearing a clap of thunder; feel nervous and at a loss on hearing sth. mentioned which sb. personally has some concern with]

闻问英雄惊煞人，

雷霆巧借应变神。

失慌才志被识破，

箸落辩说掩饰真。

比喻借别的事情掩饰自己的真实情况。Metaphor is borrowing from something else cover cover own true truth.