BiP co-star Alex Nation also agreed: 'You were shook, all the girls were shook! It's just really disappointing.'
Meanwhile, former Bachelor contestant Keira Maguire has her own theory on what the secret could be.
Speaking The Buzz podcast last month, the former Bachelor star said her sources had told her Brooke will finally reveal the real reason she left The Bachelor before the finale, despite being an early frontrunner to win the show.
According to Keira, Brooke decided to leave early after Nick confessed he was already planning on dumping both finalists.
'Apparently, she's going to come out with this explosive reason why she left [The Bachelor],' Keira explained to co-hosts Joey Carroll and Mikkayla Mossop.
'[Nick] told her something… I heard he told her that he was going to choose no one. But that's a rumour, so you just don't know what to believe.'