In scenes to air tonight, we'll see Calum telling housemate Michelle Visage that he locked lips with Katie years ago when he was "wasted".
Katie then reveals that Calum asked her to spit in his mouth. Um, GROSS!
When Katie made her late entrance to the house last week, she actually said she couldn't quite remember whether or not she'd ever snogged Calum.
"I either kissed him or spat in his mouth, one of the two," she said.
We guess her memory is back now, then!
Calum and Katie's conversation came after Calum told Katie he didn't mind her nominating him for eviction.
In a live twist last night, Katie was called to the Diary Room and asked to save one housemate from eviction and nominate another.
She chose to save Katie Hopkins and put Calum up instead, saying she knew Calum wouldn't go home as he is so popular.
Calum said today: "I have no problem with her doing that at all," he said. "I'm good. I'm at ease. I feel cool, calm and collected. It's no problem. It's all good, my friend. I'm all good!"
He also said: "Friday is two weeks down and I said I'd be ready to go after two anyway."
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