The pair, who are lined up as the future stars of children's television, made their big debut -- and then landed a major slip of the tongue.
They appeared after 11pm on the iconic show, with host Ryan Tubridy trying to calm an overly enthusiastic crowd before he introduced the 18-year-old Lucan natives.
The determined X Factor rejects had been spotted practising their lines together before their big moment in front of the nation, clad in matching gold suits.
On stage, John demonstrated to the audience how he could walk on his hands, before doing the splits. It was then he inadvertently uttered the words "Oh sh**". Looking worried, he said: "I ripped my pants."
"That's okay," said Ryan.
"Oh my God, that was not planned," John said.
The incident was over in the blink of an eye and, thankfully, John's trousers looked fine.
The boys had to be protected by a team of 10 security guards as they attended the show and were given the red-carpet treatment usually reserved for Hollywood A-listers, arriving to and leaving the Donnybrook studios via a back entrance.
An excited Edward said: "It's our first Irish appearance ever. What a way to start it."
An RTE spokesperson was unable to confirm earlier today whether any complaints had been received from the public about the swearing incident.