by Radar Staff
What comes after 'Sweet 16' -- 'Sassy 17?'
Tallulah Willis -- the youngest (and underage) daughter of Bruce Willis and Demi Moore -- showed off her rebellious side at the Coachella Music Festival in Indio, California on Sunday.
Tallulah -- wearing a bikini top and jean shorts that exposed a tattoo -- was snapped smoking a cigarette, even though she's doesn't turn 18 until next February.
Like her dad, mom and older sisters Rumer and Scout, Tallulah is following into the family business and pursuing a career in acting.