The British singer has confessed she was attracted to the 'SexyBack' star for a long time, but her crush went away once she met him.
Leona – who worked with Justin on new track 'Don't Let Me Down', which appears on her upcoming album 'Echo' – said: 'I had a big thing for Justin before I worked with him, but I lose my crush when I meet people. Which is probably good news for my boyfriend Lou!'
The 24-year-old pop star – who is in a long-term relationship with Lou Al-Chamaa – has also revealed she turned down the chance to kiss 'Gossip Girl' heartthrob Chace Crawford in the video for her single 'I Will Be'.
She said in an interview with the latest edition of Sugar magazine: 'They wanted me and Chace to kiss in the 'I Will Be' video. But I said no way. I'd just have been too embarrassed, he's my friend! He's so beautiful, I mean, look at him - he could be a girl. He'd be a really pretty girl. But I just don't think of him like that. And it wouldn't be fair to Lou to kiss other guys.'