The duo often dress up as Disney characters and sing and dance for their BGT performances.

This time around, they tackled Frozen 2's Into The Unknown, dressed as Elsa and Olaf.

Joe performed a tap routine, while partner Katherine took on Elsa's high notes.

Last time the duo appeared, Joe confessed to host Ant that they were related, having found out after Ant's family tree series with Dec, called DNA Journey, which aired last year.

BGT's Ant McPartlin said one act appeared 'upset' over the comments from the judges

But not even this family link was enough to get the judges on side this time around.

As Joe and Katherine finished their performance during Saturday's fourth semi-final, they were left a little sad by what the judges had to say.

Amanda Holden, Alesha Dixon, Ashley Banjo and David Walliams were divided, as many of them couldn't understand what they had watched.

Katherine O'Malley and Joe O'Malley took to the BGT stage

Ant and co-host Dec Donnelly tried to look for the positives, in saying they were what the show was all about.

David even gave them a standing ovation, praising the pair, while Alesha pressed her buzzer - claiming she wanted them to do the crab again.

They certainly had viewers singing along, but unfortunately the judges didn't have much nice to say.

David Walliams gave Katherine O'Malley and Joe O'Malley a standing ovation

Amanda even advised Katherine to go solo, leaving Joe unsure what to say - only for Ashley to make it worse by mocking his dancing skills, and the fact he had fallen over.

Dec joked he was melting and sweating in his snowman costume, but Joe stayed silent.

Joe introduced himself to relative Ant earlier this year

Ant and Dec said goodbye to the pair, with Olaf walking off the stage with his hands in the air, before Joe smiled to the viewers cheering at home.

Ant said: "We have got one very upset snowman, that's what I can say."

Britain's Got Talent continues Saturdays at 8pm on ITV.