laugh up your sleeve
to be secretly amused.
laugh up your sleeve
to be secretly happy, especially
because you have played a trick on someone or criticized them without them
knowing
laugh up your sleeve即是暗地裏偷笑 尤其是因為劇弄了別人或批評他們而他們是不知道的
2009-10-29 18:28:47 補充:
例句:
They're very polite in your presence, but you get the feeling they're laughing up their sleeves.