Busted were banned from hanging out with McFly in their early days.

The two groups shared the same management team, and executives were keen to keep the acts apart during their down time in case the 'Year 3000' hitmakers' wild partying ways led their "clean cut" rivals astray.

Busted's Matt Willis told the Sunday Mirror newspaper: “Back in the day, Busted’s management, who also managed McFly, would never let me hang out with them. I was never allowed at anything they were doing. They’d say, ‘Matt, you’re not allowed, they’re really clean cut, really well behaved.’”

But after joining McFly for a Brit Awards afterparty at their house, Matt quickly realised their image was all an act.

He said: “I just thought, ‘These are f****** reprobates. That night… it was messy.”

And bandmate James Bourne admitted: “I broke into the McFly house once. I climbed up the drainpipe into the window on the second floor, and they were all stoned in the cupboard.”

McFly drummer Harry Judd laughed: “He scared the s*** out of us. We were up to no good… we thought the police were coming.”

The two bands - who have previously toured as supergroup McBusted without Busted's Charlie Simpson - are teaming up for a joint tour next year in which they will go head-to-head and they've got "hundreds" of ideas for the concerts.

James said: "The idea is that each band will perform, then we’ll come together to battle it out. There’ll be laser beams shooting out of guitars, and at the end some kind of winner.

“I love the idea of it being a McFly show, and then they sing 'Bubble Wrap' – and the first you see of Busted is Charlie coming down from the ceiling like an angel, singing the chorus.

“I’ve got a hundred of those ideas. I wanted to have the intro like in ET, with seven of us flying in on BMX bikes in the sky. That would be epic.”

Matt insisted the tour will be like nothing anyone has seen before.

He said: “The exciting thing about this is that no one’s ever done it before. I’m not sure what other bands could – they wouldn’t have the same history as us.

“We’re intertwined, you can’t talk about either without mentioning the other. That’s why this works so well. We want it to be more than just two shows in one, there’ll be fun bits.

“There’s a thing that happens with us when both bands get together – it takes away the need to try to make the gig cool. We just say right, let’s make this the most entertaining, fun f****** show you could see.

"Let’s throw all these creative ideas at the wall and see what sticks. It’s no holds barred.”