Demi Lovato might be the youngest judge on X Factor, but she has the strongest voice — and we aren't just talking about her songstress skills! Demi's an active supporter of Secret's anti-bullying campaign, Mean Stinks — in part because of her own struggles with bullying as a teenager.

Now, Demi wants to show her younger sister that she's strong enough to fight back against bullies! “My 10-year-old sister Madison means the world to me,” Demi tells Hollywood Life. “I wanted to be a good influence for her and show her that I could raise my voice about issues like bullying and eating disorders and get help.”

Demi and Mean Stinks are working together this October (National Bullying Prevention Month), and Demi hopes to inspire other young girls to share advice and stand up for each other.

“[The campaign] is targeted for young women and young girls,” Demi says. “Tell your friends! Make the pinky pledge! We do this thing called the Pinky Pledge — we paint our fingernail blue on our pinky and blue is the color of hope, so we pinky promise each other that we’re not going to bully each other. Make the pinky promise with your friends!”

Sigh, this is taking the art of pinkie swearing to a whole new level.

Source: Hollywood Life