Hijacker Jimmy Carr told the housemates that he was setting them a bonus round in the Mates Rates quiz.
He told them that he would make each housemate stand on a podium in the garden, dressed in their different animal outfits, and they would have to guess the subject for what rank they had been placed in.
Calista was ranked at the 'least' end next to Emilia, while John and Anthony were standing at the top end next to the 'most' sign.
John suggested that it was in order of height, while Amy insisted that they had been placed in their honesty ranking.
After about 45 minutes they were still left guessing and Nathan came up with a brain wave, telling Amy that it could be the order of how likely they were to win the show.
An impressed Amy told him that it was "phenomenal thinking" and that because girls "never win Big Brother" that he could be right.
But when Nathan tried to explain, Emilia worried: "If that's right, me and Calista are going tomorrow."
"I'm not saying that's what I believe," Nathan reassured the two girls, but an upset Calista told him: "I think it's completely pointless us speculating, you have no idea."
Emilia also got upset and told the musician that it felt like he was saying that he thought both her and Calista will be the next people to leave.
Nathan walked out of the bedroom to defuse the situation, telling them: "You're taking what I said personally."