The 21-year-old singer used the demise of her relationship with her writing partner and the group's guitarist Josh Farro as the inspiration for many of the tracks on their 2009 album 'Brand New Eyes' and admits it was "embarrassing" showing him her lyrics.
She said: "The entire record concerns not just my dating relationship with Josh, but the relationships between all of us. It's about the ways the other guys reacted to me and Josh, and to me. I definitely felt very secluded.
"It was more embarrassing after the split. We'd get into arguments and he'd be like, 'Why can't you write in front of me? It shouldn't be that big of a deal, you know me.'
"Before, he felt a part of the lyrics, when we were hitting everyone else head on. Now we were colliding."
Hayley - who along with her former boyfriend is joined in the group by Josh's brother, drummer Zac Farro, bassist Jeremy David and guitarist Taylor York - felt particularly uncomfortable performing the song 'Ignorance' to her bandmates for the first time.
She recalled: "I tried to mumble all the way through but Taylor was right next to the speaker and heard every word. He gave me this fierce look - I thought he was going to kill me - and said, 'So do you want to tell me about those lyrics?' I ran into the bathroom, I was so nervous.
"But we talked for two hours and reconciled a lot of tough, heavy things. That song saved our band.
"It can be a little hateful, but very hopeful as well, and that's the important message. It shows we're not just teenybop superstars."