The former Strictly star has joined the judging panel alongside Alesha Dixon, Amanda Holden and Simon Cowell after the departure of David Walliams, who left the line-up after it emerged that he had made insulting comments about contestants.
And he’s now confessed he was totally new to the programme.
He explained during an interview on This Morning: “This happened really last moment. I had no idea.
"Never seen the show.”
"No idea what was going on," he added.
Tonioli joked that he was given the idea there were no real rules, other than just being himself.
But he went on: "It was a wind up because in fact there are rules and I broke them immediately with the Golden Buzzer!
“Something happened that was so extraordinary and I just went for it.
“You are supposed to do it after they have finished the performance and I did it mid flow, yes, I just went and whacked it.”
The star, 67, revealed that everyone on the show had been wonderful to him since he joined and that he felt very comfortable.
"I was petrified," he admitted.
"You are entering a long-running huge hit. They have been doing it for years. It's Simon's baby. They are all friends… but in fact it felt like home.”
There have been rumours about the dancer causing a lot of laughs on set with his hilarious antics, and last month his fellow judge Dixon was quizzed about it when she appeared on ITV's Lorraine.
Laughing, the TV star admitted: "I have a few Bruno bruises as I like to call them - he likes to grab the arm!"
"I don't think he's got the rules yet, no!" she told presenter Lorraine Kelly.
"I think after day two we just turned to each other and said, 'Let's just throw the rule book away!'"
Watch: Alesha Dixon's daughter wants to prank Bruno Tonioli