The 'Come and Get It' hitmaker, who recently admitted to being starstruck by Cooper, said she could not contain her excitement when they met, reported Conatctmusic.
"I just remember seeing him and freaking out and running away very quickly afterward. That seems to be the thing I do. It was surreal. He was so beautiful. I told him I was a big fan. I'll have a restraining order soon," she said.
The 21-year-old beauty is set to launch her Stars Dance tour in support of her first solo album and was equally awestruck after seeing Beyonce live on tour.