The Take That singer was performing in East London when he reportedly said to his fans: "I'm serious. What are we going to do about Rylan?
"I might have to be honest on Saturday night and go, 'Rylan, I thought that was absolute s**te'."
We take a look back at other famous X Factor feuds involving judges and contestants - from Tulisa Contostavlos and Kelly Rowland's Misha B falling-out, to Cher Lloyd's Cheryl Cole singing jibe.
Photo gallery - X Factor's famous feuds: