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.
(..) If you don't like it, then just get your own blind spot. How about I give you one? Blind spot, yes. Deaf spot, not so much. Hey, so, how would one sneak up on a Night Fury? No one's ever met one and lived to tell the tale. Get in there! - I know, I know, but hypothetically... - Hiccup! (..)2010 How to Train Your Dragon