Six hunks entered the audition room at Edinburgh's Assembly Rooms on Tuesday evening (1 July) presenting themselves as boy band, The Highland Fling.
However, unknown to Cheryl, Simon was about to give her a massive shock!
Teasing Cheryl's present some hours earlier, Simon told the Daily Record: "It wasn't difficult. I got her something she wants."
Dressed in black trousers and white T-shirts, the lads told Cheryl and fellow judges Simon, Mel B, and Louis Walsh that they were going to sing the Proclaimers song 'Five Hundred Miles', reports the newspaper.
After singing for a little while, the lads wasted no time in unveiling their true identity and soon whipped off their clothes.
The strippers jumped onto the judges' desk to serenade Cheryl - and it looks like they put on quite a raunchy performance!
While Louis and Simon laughed throughout, it is said a "mortified" Mel ran off in horror!
Cheryl can be seen with her head in her hands - probably a little embarrassed?! - as the dancers stripped and performed dance moves around her.
Cheryl turned 31 on Monday (30 June) and achieved the impossible while on a private plane to Scotland, as she managed to get Simon to wear a party hat - and the music mogul even cracked a smile!
It wasn't long before Simon made a dig of his own though, tweeting this week: "Now what shall I get Cheryl for her birthday? 40 is an important year."
After Simon's strip prank, we wonder if Cheryl is plotting her payback?!
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Watch Cheryl's video for 'Crazy Stupid Love' below: