Calum was spineless when Perez shared what he got from the poem that Calum's mum gave to him. Perez said there was a secret message in it and Calum seemed to appreciate this, i.e. giving no hint of finding it distasteful.
However, Calum then went into the bedroom and blabbed about what Perez had said...clearly dissing the guy. Whilst there is no love lost between Calum and Perez, it showed him to be 2 faced and fake. Why couldn't he be upfront and tell Perez to his face what he really thought? I doubt if it was because he didn't want to offend him. Hmmm