laugh up your sleeve
US /læf ʌp jʊər sliːv/
UK /læf ʌp jʊər sliːv/
1.
reírse por dentro, reírse a escondidas
to be secretly amused about something, often at someone else's expense
:
•
She tried to keep a straight face, but I could tell she was laughing up her sleeve.
Intentó mantener la compostura, pero pude darme cuenta de que se estaba riendo por dentro.
•
The politician pretended to be concerned, but everyone knew he was laughing up his sleeve at the public's gullibility.
El político fingió estar preocupado, pero todos sabían que se estaba riendo por dentro de la credulidad del público.