The former Love Island star said he will be voting for the former Strictly professional to be put through his paces in the camp.
AJ is one of 10 stars facing their fears on the ITV reality show, including Shane Richie, Sir Mo Farah and Victoria Derbyshire, as the show is filmed in Wales for the first time due to coronavirus.
Curtis told ITV’s Lorraine: “If there’s going to be a trial for him, he mentioned he doesn’t like rats, anything to do with rats, he doesn’t want anything to do with.
“He said he will be scared to the bone. And confined spaces. So if you’re going to put him in a coffin with rats, let’s see what happens.”
He added he will “absolutely” be voting for his brother, adding: “I want him to do as many trials as humanly possible, I want to see him cry, scream, maybe throw up, I’m the worst brother ever.
“What a lot of people don’t know is me and AJ did a lot of extreme sports when we were younger so we were in the cold, the wet and the mud and that never affected us, but as AJ has got a little bit older, I’m not going to lie, he’s become a little bit more squeamish.
“So he is scared of spiders now, he is a little bit scared of heights, so I think he’s actually going to be shocked with himself on this, I think it’s going to really scare him in ways he didn’t expect.”
AJ was in isolation for more than two weeks ahead of going onto the show and tested positive for coronavirus.
— AJ Pritchard (@Aj11Ace) November 15, 2020
However, Curtis said he has never suffered any symptoms, adding: “I believe he was completely fine, he just came back positive and then it came back negative and he’s been completely fine since.”
He also apologised to all the people he deceived while keeping the secret that AJ was going on the show.
Curtis said: “He did tell me, I had to lie to so many people, I’m so sorry if you asked me and I completely lied to your face but I found out a while ago, it must have been two odd months, maybe a little bit longer ago.
“But then he was in lockdown for two and a half weeks, that lockdown he was in Wales and he had his phone and he said the weather here is horrible, the wind the rain, how cold it is, I said that is just the start AJ, wait until you’re eating some sheep something or this or that, it will be horrible.”