Girls Aloud star Cheryl is reportedly worried about her former band mate Sarah Harding joining Celebrity Big Brother.
Although not confirmed, Sarah is rumoured to be among the celebs set to enter the CBB house this summer.
She is one of sixteen names on a leaked Celebrity Big Brother line up ahead of Tuesdy's live launch show.
And Closer magazine reports that Cheryl is worried about what Sarah could say in the house.
"Cheryl isn't very happy at the prospect of Sarah going on CBB," a source told the newspaper. "She's worried that Sarah can be a bit unpredictable at times and is concerned about what she might say about her."
The insider added: "She and Sarah go back years and have supported each other through tough times.
"She doesn't want Sarah talking about any of their past spats or about any of her previous relationships.
"She doesn't want personal or painful memories from the past being brought up."
Whether or not Cheryl's supposed fears are realised will only be revealed on Tuesday when the celebrity housemates are confirmed.
Alongside Sarah, those rumoured for Celebrity Big Brother 2017's summer line up include YouTuber Trisha Paytas, The Real Housewives of Beverly Hills' Brandi Glanville, X Factor's Amelia Lily, Gogglebox’s Sandi Bogle, TV psychic Derek Acorah and Absolutely Fabulous star Helen Lederer.
Joining them on a leaked list includes American Star of The Bachelor Chad Johnson, Reality star Jordan Davies, Real Housewives of Cheshire star Dawn Ward, Ex EastEnders actor Shaun Williamson, reality star and Hollyoaks actor Paul Danan and Ex On The Beach star Jemma Lucy.
And more rumoured celebrity housemates are Made In Chelsea's Sam Thompson, Mob Wives' star Marissa Jade and daughter of Chris de Burgh and model Rosanna Davison
Celebrity Big Brother 2017 starts on Tuesday, August 1 at 9PM on Channel 5.
The new series is expected to run for around four weeks.