The CNN chat show host was sharing a flight with the 60-year-old star and revealed he was woken up repeatedly, eventually ''to the sight'' of her naked chest right in front of his face.
He told the Daily Mirror newspaper: ''We were incarcerated on a small plane for five hours flying to Los Angeles. I love Sharon but she was in a frisky mood after a coupe of glasses of red wine.
''I needed to sleep but every time I tried she'd wake me - shrieking and poking my nose or pulling my ears. I finally drifted off, only to get woken again.
''I opened my eyes to the sight of Sharon's naked right breast dangling two inches from my eyes.''
The 48-year-old star joked it was simply not the right time nor place to have the 'X Factor' UK judge's breast exposed to him.
He added: ''There is a time and a place for Sharon Osbourne's naked breast. But dangled in my face at 3am in the confines of a private jet really isn't it.''
An album re-release, a new song and a documentary mark the singer's legacy this year.
The actor plays the titular hero in the forthcoming adaptation.