The Vamps at Radio 1's Big Weekend
The Vamps said they are "very excited" to be performing their song Last Night on the Britain's Got Talent semi-final.
They will be joining other stars including X Factor's Ella Henderson, Ed Sheeran and will.i.am on Wednesday.
Speaking to Newsbeat at Radio 1's Big Weekend, drummer Tristan Evan said he's looking forward to it "because we've watched it for ages".
He added: "I used to watch it and it was really fun. We're going to get three 'nos' but it's fine."
The band had to tell Tristan it's actually four "nos".
He replied: "I watched it like 20 years ago when there were three judges".
'Almost naked'
The group also told Newsbeat about some of the crazy things their fans have done.
Guitarist James McVey said: "We love them, they're like family.
"Me and Connor were staying in Manchester in a hotel room. There was a knock on the door and we thought it was Brad.
We had our door on latch, so we said come in, six girls ran in and we were almost naked. That was pretty weird."
The latest contestants to get through to the Britian's Got Talent finals are 15-year-old singer James Smith and a 26-strong street dance crew, The Addict Initiative.
They beat seven other acts in the second semi-final to join singing group Collabro and illusionist Darcy Oake, who were winners on Monday.
Just 45 acts have made it through to the live semi-finals from the thousands who applied and the hundreds who auditioned.
They are battling it out for the prize of £250,000 and a spot at the Royal Variety Performance.
The live Britain's Got Talent semi-finals will air at 19:30 BST on ITV1 between 26 and 29 May.
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