"I cried more when she told me to get up there," Brandon told WPTV of the big moment with his hero. "I didn't think it was really happening, it was unbelievable."

Stefani is one of several high-profile names to act against bullying in recent weeks. Ghostbusters star Leslie Jones was forced to quit Twitter because of racist cyberbullying last month and called on the social network to do more to stamp out hate.

An emotional Jennifer Aniston spoke out against cyber-bullying in front of an audience of young fans at the Giffoni Film Festival in Italy, calling trolls "cowardly," while Prince William released an anti-bullying video for Stand Up To Bullying Day.

Image: Instagram

Warning: Watching Gwen Stefani bring a young fan on stage may make you cry