Fans of the show took to Twitter to point out Sonia's wording of the question, with many remarking that live TV is not her forte.
"Sonia: 'So Chad & Sophie....have you f***ed yet?' The question all of Australia was wanting to know #BBAU #BigBrotherAU #BBAUFinal," one social media user joked.
"Sonia is terrible at live TV," another remarked.
Chad and Sophie agreed that should either of them win, they'd split the $23,000 prize money between them and appear to still be together despite living in separate states.
However their former housemate Daniel Gorringe didn't have much faith that they'd split the winnings.
"If they split that money, I'll eat my left shoe. It's very hard when the money is in front of you. They might prove me wrong and I hope they do," he said.
"Sophie and Chad would deserve that win if they get it."
Chad and Sophie, who live in Sydney and Darwin respectively, were reunited at the live finale but are yet to comment on the prize money situation.
"Arhh Speechless. Honestly thank you so much Australia it means a bloody lot to me ❤️ arhhh!!!! And thank you @bigbrotherau for the letting me In your house. Love you maa! All for you dad❤️ #moralsovermoney," Chad wrote on his Instagram page.
Sophie shared her support on her own platform captioning a photo of Chad with: "Winner winner chicken dinner! Gosh I’m so proud of you @chad_hurstt ❤️❤️❤️ very well deserved."