A furtive activity could become mainstream.

偷偷摸摸可能成为主流。

youdao

He pushed it gently with the tip of his finger, lightly, with the furtive and uneasy gentleness of a cat which is desirous of entering.

他用指尖推着，轻轻地、缓缓地、正象一只胆怯心细、想要进门的猫。

youdao

With a furtive glance over her shoulder, she unlocked the door and entered the house.

随着越过其肩的鬼鬼祟祟的一瞥，她打开锁进了那房子。

《柯林斯英汉双解大词典》

He evinced a furtive joy in the misfortune he was causing, a kind of surreptitious euphoria, and it was not entirely foreign to his host.

NEWYORKER: Heirs

Narrow spaces and hidden places would naturally matter enormously to a furtive child, and Scorsese chases after Hugo down tunnels and along passageways and up a stairway to his room the view up the stairway keeps telescoping in depth.

NEWYORKER: Fantastic Voyages

His only corroborating evidence is an ambiguous taped conversation of a furtive airport meeting.

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