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.
(..) You gave me life. Oh, God, I don't want to go. Yes, you do! What, are you trying to sneak out on us? - Bye, Aunt Claire. - Bye. Bye, Anthony. - Gonna come visit me in New York? - Yes. (..)2005 TvShow: Six Feet Under Title: Everyone's Waiting Season: 5 Episode 12