surreptitious
adj
(usu derog 通常作贬义) done or acting secretly or stealthily 暗中进行的; 偷偷的
a surreptitious glance 偷偷的一瞥
She carried out a surreptitious search of his belongings.她暗地里搜查他的东西.
I don´t mind you smoking occasionally -- there´s no need to be so surreptitious about it! 你偶尔吸烟我倒并不介意--何必这样躲躲闪闪!