'I was not expecting that at all,' Cass says. 'I was actually completely shocked.'
'He told me not to tell anyone... He's gonna hate me for this,' Brooke adds.
She doesn't reveal what the secret actually is, so viewers will have to tune in to find out.
Brooke was one of the final three in the Nick Cummins' season of The Bachelor, but famously walked after she felt she was not getting the answers she needed from the sportsman.