The Geordie singer, 31, split from first husband Ashley Cole after multiple reports of his infidelity, despite initially giving him a second chance.
READ: CHERYL FERNANDEZ-VERSINI WANTED TO KEEP WEDDING A SECRET: "UNFORTUNATELY IT WAS LEAKED"
During the latest round of X Factor auditions Cheryl warned the new contestants not to cheat on their partners, an eyewitness confirmed to the Mirror.
The audience member said: “Simon was asking if they were hiding secret girlfriends.
“Cheryl just leapt in and said that if they were they musn’t cheat on their lovers. She left them in no doubt she was deadly serious. It raised a few eyebrows, because everyone knows what Ashley Cole put her through.”
VIDEO: CHERYL FERNANDEZ-VERSINI TWERKS UPSIDE DOWN AGAINST A WALL
Meanwhile, Cheryl and Simon, 54, were reportedly ‘at loggerheads’ during the auditions over the age limit for young contestants.
Simon slashed the age-limit from 16 to 14 for the new series, but Cheryl does not agree.
The Crazy Stupid Love singer allegedly told Simon: “I don’t think a 14-year-old needs that pressure on his shoulders. He’s got to do his GCSEs.”
To which Simon replied: “In Cheryl’s opinion anyone under the age of 16 shouldn’t be on this show.”
READ: X FACTOR VOICE OVER MAN TOLD TO START PRACTICING CHERYL'S NEW SURNAME
An X Factor source told the Mirror: “Cheryl thinks the most important thing for a 14-year-old to do is their schoolwork.
“Simon knows there is a lot of young talent and wants to widen the net.
“He is conscious that younger singers need to be relaxed and not have too much pressure on them.”