The former Girls Aloud singer had sworn not to mention the former ‘X Factor’ judge - or indeed any of her former bandmates - before she entered the reality TV compound, but it didn’t take her long to break.
Sarah hinted at her feud with Chezza as she revealed they hadn’t spoken for nearly three years.
She made the revelation in a conversation with housemate Jemma Lucy about height, of all things.
When Jemma asked how talk Sarah was, the 5ft 5in star said: “When I’m in heels, I look much taller.”
Completely unprompted, Sarah then brought the rest of the girls into it, continuing: “I always looked the tallest when I was in the group. I look like a giant next to Cheryl. She’s like a Polly Pocket, she’s very petite.”
“Do you still speak to her?” asked Jemma.
“I haven’t spoken to her in a while, the last saw her when we were doing ‘The Xtra Factor’ and stuff,” Sarah revealed.
After being asked if they fell out, Sarah responded: “Everyone’s asking that, we’re just so busy with our own stuff, do you know what I mean?
“It’s not for me to say, honestly,” she continued.
“Yeah, it’s not for me to say, I don’t like talking about the other girls if it’s a personal thing. We were like sisters so of course it was never going to be plain sailing the whole time.
“Having been around girls the whole time it’s difficult sometimes.
“Nothing is forever. We went through a lot together, so nothing lasts forever. We went through so much. Even if we had fell out I’m sure it wouldn’t be a major deal in the future.”
Sarah last appeared on ‘Xtra Factor’ November 2014, when she came out in support of Cheryl and her one remaining act, Lauren Platt, suggesting that was the last time they spoke.
Prior to entering the house, Sarah told OK! magazine: “I don’t know what she’d be worried about, but at the end of the day, if I went in there I wouldn’t talk about the band or any of my exploits.
“I’d go in to show people who I am as a person. I’m a loyal friend and I’m not going to go in there and talk about what’s gone on.
“We were like sisters at the end of the day, so I wouldn’t go in there to talk about the band or their secrets.”
Cheryl recently sparked rumours of a falling out with Sarah when fans noticed she’d unfollowed her on Twitter.
However, Sarah played this down during the interview, saying: “It’s nothing to do with me.
“I’ve got Cheryl’s number - we don’t have to prove we’re friends online.
“I’m a private person and if I want to speak to any of the girls, then I’ll call them.”