This week viewers were rocked by Married At First Sight Australia's biggest scandal yet. Following a wild night out on the town Michael and Hayley cheated on their spouses with one another. But it was Hayley's "husband" David's act of revenge that has blown viewers' minds and taken the show to a whole new level of depravity.
In a move that defies belief David took Hayley's toothbrush and used it to clean faecal matter from the toilet.
Hayley unknowingly went on to use the toothbrush for several days before the truth was revealed.
All of the sordid details came out during the series' third and most explosive dinner party yet.
And as the experts watched on, Mel Schilling began dry wretching, saying "That's disgusting. That could make her very sick."
David has explained his despicable act in news.com.au's Not Here To Make Friends podcast, saying:
"About three days after the cheating scandal happens, I've heard nothing from Hayley and I'm in a really dark place … I still had her room key, and that's when I did something really childish.
"I knew she liked her equal in her coffee so I flogged that, I knew she liked clothes folded in a certain way, then while I was getting my toiletries out of the room, that's when the whole toothbrush incident happens.
"She would go to the toilet without cleaning up after herself... I wasn't a fan of the ... what she would leave on the toilet bowl, so that's when I grabbed the toothbrush and scrubbed the toilet with it."
He said she used the toothbrush for five days.
"It's her own poo, it's her own bacteria in her own body so it's not going to hurt her," he theorised.
But his vengeful act could come back to haunt him. Hayley was understandably outraged and has threatened to call in lawyers, an insider has revealed.
Production of the hit reality TV show was shut down for two weeks after that, and the dinner party in which it all comes out was filmed when production resumed.
In a double twist viewers were horrified when Stacey put the blame for her husband's cheating squarely on Hayley.
Stacey unleashed on Hayley for taking advantage of her "vulnerable" husband, saying, "It's her word against his. Who's lying?"
Stacey has since explained to Today Extra that she had fallen for Michael and really wanted to believe him when he said he hadn't kissed Hayley.
"Now I think she didn't deserve that," Stacey admitted.
Stacey said that off camera Hayley had told her she hadn't kissed Michael "and then she changed her story and said she did".
"I felt manipulated by her, I felt like I had to go in there and say what I needed to say to get it off my chest."
But the toothbrush....
"No one deserves that."