The 23-year-old singer admits she's ''so proud'' of the 'Lego House' hitmaker - who joined on her on 'Red' tour this year - after he sold out three nights at Madison Square Garden in New York City earlier this month and she's confident he'll go on to achieve great things.
Speaking to Capital FM, she said: ''I think for him, success worldwide is inevitable. That's going to happen. He's amazing, he's talented, he's got an amazing record.
''The fact that it was able to happen so quick is what I was so proud of because we'd played a stadium in New York a couple months ago and then they put the tickets on sale for Madison Square Garden.
''And clearly, everyone who saw us, a huge percentage of them wanted to see him. That really shows a lot - that the fans were willing to go, 'You know what, I want to see that guy do his own show too.' ''
The flame-haired hunk is set to release his second studio album early next year after debuting two songs, 'So In Love' and 'New York', during his US shows.
'The Art Of The Deal' how you've never seen it before.
Shot on a plane in zero gravity, the video features OK Go's usual levels of choreography with a few surprises thrown in for good measure!
The Boss will release his memoirs via hardback, audiobook and e-reader on September 27th 2016, and reportedly secured a $10 million advance.
His wife is on the warpath now.