Lee, 30, and his bandmates - Duncan James, Simon Webbe and Antony Costa - first found fame in 2001 after releasing their debut single 'All Rise'.
In 2001, Lee started dating Atomic Kitten's Liz McClarnon and they got engaged in 2003.
The couple split soon after, however, and it was rather awkward when they both found themselves on The Big Reunion last year!
Lee has two children from previous relationships, a son called Rayn and a daughter called Bluebell.
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Copyright: Channel 5