“For our tour they’re all going to wear T-shirts saying ‘I’m Josh’s mum’ with photos of us now and when we were little,” Bretherton told North West Tonight.
Unbeknownst to each other until the day itself, the pair both auditioned in Liverpool.
Bretherton said his friend had called him asking him what he was doing, and “I said, ‘I’m going to audition at this Simon Cowell boyband thing and he was like, ‘me too’ and I was like, ‘no way’ – see you there then’.”
The band also includes Cruz Lee-Ojo, 19, Hendrik Christofferson, 19, John Fadare, 17, Nicolas Alves, 17, and Seán Hayden, 19.
Bretherton and Olliver, who once ran a car washing business together in their home town, said they had been talking to their bandmates about Chorley and had even recommended a trip to their favourite kebab shop, The Nile.
The band have been signed by EMI Records, with the Netflix series first airing on 10 December, which is how they got their name.
Hendrick said they had been chanting “December 10, December 10” as they excitedly looked forward to the release date, and it stuck.