Both judge Louis Walsh and viewers at home were left furious after Simon Cowell bent the rules for singing duo Max and Harvey during Celebrity: X Factor 's Movie Week tonight.
The music mogul, 60, allowed Max and Harvey to perform popular One Direction track 'Kiss You' from their movie 'This Is Us'.
After the twins' energetic performance, Louis, 67, slammed Simon for 'bending the rules' and allowing them to sing a song that questions the definition of what qualifies as an approved track for Movie Week.
After Nicole revealed she was on the Max and Harvey train, Louis said: "Every week you deliver and you actually remind me of One Direction the first time they sang.
"It is the energy, the positivity, and I love the fact you sang one of their more unusual songs. You are ready made..."
The Irish judge then questioned Simon: "The theme is movies. What movie is this song from Simon?"
Simon rolled his eyes, before sarcastically shutting down Louis' suspicions.
He argued: "It is called the One Direction movie, which was one of the biggest music movies of all time Louis.
"You were probably in bed when the movie came out."
The judge then complimented Max and Harvey and said they brought "real energy" and said it was totally "age appropriate."
Some viewers took to Twitter to agree with Louis and question the song choice.
One user swiped: "I'm sorry the 1D movie doesn't count!!!
"Really Simon? Have Max and Harvey sing a song from an iconic Hollywood movie?"
While another insisted: "Simon is changing the rules constantly."
One viewer questioned: "One direction has a movie?"
Whereas a One Direction fan took to Twitter to correct Simon.
They shared:" The fact Simon said the movie was called One direction the movie.
"NO IT WAS CALLED ONE DIRECTION THIS IS US THE MOVIE! Get it right."
Tonight saw acts Try Star and Vinnie Jones become the latest acts to be eliminated from Celebrity: X Factor .
This means the final line up consists of The Chase's Jenny Ryan, viral stars Max and Harvey, Towie star Megan McKenna, and influencer band V5.
*The Celebrity: X Factor final will air next Saturday on ITV.
