Caoimhe has won this week's Save and Replace task on 'Big Brother'.
The Irish student - who originally faced the public vote alongside Australian John James - has chosen trainee joiner Nathan to take her place, meaning he now faces eviction on Friday night.
As part of the task - which was entitled Stay On TV - the nominees were given three attempts to ride a television-shaped bucking bronco.
John James asked Caoimhe: "How much do you want to be here? Because if you want this more than me."
However, the pair decided against fixing the result of the task after Josie suggested it could mean Big Brother may refuse to let either of them save themselves.
Caoimhe, 22, originally managed to stay on the bucking bronco for 22 seconds, but then only achieved 16 and nine seconds on her second and third tries respectively.
John James, 24, failed to stay on for longer than 20 seconds on his first and second attempts and then walked away smiling, causing his opponent to warn him not to "do anything stupid".
She threatened: "I'm going to fall off straight away then. Don't do this. Why are you doing this?"
However, the former body builder failed to beat Caoimhe's original score, allowing her to select a fellow housemate to take her place in this week's public vote.
Nathan will now face the boot alongside John James on Friday.