In a video released after last night’s eviction, the Girls Aloud star, 35, was seen getting up close and personal with the star of The Bachelor, 30.
The pair were seen trying to avoid their fellow housemates and the cameras as they sneaked off to the kitchen for a clandestine kiss, however their attempts failed.
Chad and Sarah appeared to be getting very passionate as they smooched, unaware that a camera above their heads was catching every last detail of their intimate moment.
They broke apart as soon as they realised that Big Brother could very much see them and Sarah scurried away to the pantry where she appeared to be panicking.
“I’m so screwed, so screwed,” she was heard saying as she covered her face and appeared to break down.
Sarah and Chad’s brief moment comes amid suggestions that the singer is already in a relationship with someone else.
The scenes are set to be aired on tonight’s episode of the Channel 5 reality series and come as US YouTube sensation Trisha Paytas furiously quit the house.
Following her swift departure from the house in the wake of Karthik Nagesan’s eviction, Trisha soon took to social media to hit out at the programme and declaring it was a fix.
She also launched a vitriolic attack in a series of explosive tweets to her 337,000 followers, branding Sarah “trash”.
The vlogger ranted: “She called all the older people terrible names behind their back and she has a lot of problems,” before adding: “@SarahNHarding is mentally unstable in the house and they are enabling it in ways I can’t speak about.”
The U.S. star went on to share: “@SarahNHarding talked about her boyfriend back home yet makes out with chad? Can’t wait for that b***h to face reality.”
Celebrity Big Brother continues on Channel 5 tonight at 10.30pm.