Lee, who reformed with his 90s pop band 911 for last year's Big Reunion, told fans on the weekend that Lila Rose Holliday had made it through the first two rounds of the singing competition.
The hopeful, who has been dating Lee for more than a year, would have been in the Over 25s category, however she failed to make it to boot camp.
Watching the show last night, Lee told his followers: "If only @I_Am_LilaRose had been put through on @TheXFactor. She smashed the first two rounds & was let go! #Xfactor2014 #Over25s @TheXFactor."
Lee then posted a video of make-up artist Lila Rose singing in the kitchen, so fans could see what Simon Cowell, Cheryl Fernandez-Versini, Louis Walsh and Mel B had missed out on!
This weekend, following a marathon three episodes, viewers saw the judges pick their final acts for the live shows. The X Factor singers have now all moved in together into a swanky house in London.
Yesterday, female duo Blonde Electra were pictured out jogging as they worked up a sweat ahead of the upcoming first live episode!