It's not the first time that Dexter has claimed that quiet Callum is playing a game, agreeing with Dan yesterday that there was someone in the house who was trying too hard to please everyone.
But Dex did confront Callum, warning him: "No one has said anything bad about you but sometimes take a step back and assess the situation.
"I think you're a really nice person but because you're nice to everybody it might look a bit contrived."
However Callum wasn't too impressed with Dex's comments and told him: "You can say whatever you want but contrived? Me being too nice? Chasing people around wiping arses? I wont be chaisng people around."
Dexter insisted: "I'm not saying it in a bad way and please don't take it like that."
But Callum snapped: "This is a f**ked up process. I can't be a genuinely nice person and get along with everyone because it means I am spreading myself too thin.
"I feel like a mug, it's not me. People lean on me."
Big Brother airs nightly on Channel 5.