on the sly
US /ɑn ðə slaɪ/
UK /ɑn ðə slaɪ/
1.
di nascosto, segretamente, furtivamente
doing something secretly or furtively
:
•
He was eating cookies on the sly when his mom wasn't looking.
Stava mangiando biscotti di nascosto quando sua madre non guardava.
•
They were meeting on the sly to plan the surprise party.
Si incontravano di nascosto per organizzare la festa a sorpresa.
: