Simon Cowell has hit back at his unauthorised biography, insisting it is not his style to ''kiss and tell''.

The 'X-Factor' boss is said to be ''hardly sleeping'' following the publication of journalist Tom Bower's book - which claims he had an affair with fellow judge Dannii Minogue in 2007, and that he believed his engagement to Mezghan Hussainy was a ''big mistake''.

Former 'x factor' judge Sharon Osbourne is angry at being mentioned and dragged into Simon's ''world of debauchery'', and present judge Gary Barlow was left smarting by claims Simon wanted to sack him for being ''too scripted''.

But despite allowing Tom access to his life, the 52-year-old music mogul admits he feels ''embarrassed'' by the revelations.

He said: ''It's not my habit to kiss and tell. I've never done it. I've always tried to keep my private life private, and it so unfortunate.

''So I was feeling very embarrassed and not gentlemanly at all this week because it's just not my style.

''At the same time, the guy's got the right to write the book he wants, but it has been uncomfortable, to be honest with you.''