The 23-year-old star was asked what she thinks about the music boss getting a judging role on the panel of the new US X Factor.
She said to UK's Buzz magazine: 'I remember when I met him and he went mental and locked me in a room and wouldn't let me leave. He wanted to sign me - it was when I first went to America as a songwriter.
'I'm a very respectful person and I said I wanted to meet every label before deciding, but he was such a nice guy. It's funny, I was so scared.
'I'd only been in the USA for three days when I met him. But it's great that The X Factor will have someone like him as a judge who's actually been there and done it.'