As a teenager she would 'sneak' out (of her house/apartment) at night to visit her boyfriend.
I'm going to 'sneak' a smoke. [=I'm going to smoke a cigarette while nobody is watching]
She took a 'sneak peek' [=a secret look] at the birthday presents hidden in the closet.
(..) Uh the severance package I think it expires all at once, not within the calendar year... Is she home? Maybe just leave it tonight. No she knows better. She can't sneak around like this. -Marion... Christine. You can't leave your room like this. I didn't. -None of these things were put away right. (..)2017 Lady Bird