Experts John Aiken, Mel Schilling and Alessandra Rampolla used to be a little more accommodating with these couple swaps, but this year have put their foot down regarding Daniel Holmes' relationship with Carolina Santos.
"We don't see any merit for this relationship, that you have to continue on in this experiment," the trio said.
So, let's take a look at the other contestants who have done the dirty on MAFS over the years:
Dean Wells and Davina Rankin
The show may have been experimental during its first seasons, but the drama ramped up from season five in 2018.
Dean Wells and Davina Rankin were first to rock viewers with a cheating scandal.
They had both been married off to different partners, but when they found themselves attracted to each other, nothing was going to hold them back.
"I feel like you and I like each other more than anyone else in that room," Davina told Dean, as the couple snuggled up on a sofa out of sight of everyone else. Dean agreed.
The viewers, however, were furious at the duplicitous pair.
Sam Ball and Ines Basic
The 2019 season continued to be a real soap opera and Sam and Ines had one of the most controversial storylines.
The couple hooked up behind the backs of their respective "spouses" after weeks of secret messages, meet-ups and flirting.
"They belong with each other," Sam's 'wife' Elizabeth told TV WEEK after the show had aired.
"They would act sweet to my face and then tear me apart behind my back.
"I think they're disgusting."
Jess Power and Dan Webb
Also in 2019, Jess Power's head was turned when latecomer Dan Webb joined the experiment.
When Cyrell revealed the two had been fooling around behind the backs of Tamara and Mick, Tamara confronted Jess.
"The first time Dan and I ever walked in here together, she followed him around like a bad smell," Tamara said on the show.
"The second week she did the same thing.
"And then tonight Cyrell dropped a bombshell that I didn't know happened."
Jess denied it, but when their respective partners voted to leave the experiment at the next commitment ceremony, Dan and Jess asked to stay ... with each other!
Hayley Vernon and Michael Goonan
It wasn't until the show was over that Michael Goonan confessed to fooling around with contestant Hayley Vernon behind Stacey's back in 2020.
He swore it was just a kiss on a drunken night out, but Vanessa Romito disagreed.
“I swear on my life Hayley and Michael hooked up,” Vanessa told New Idea.
“It definitely happened.
“They were fooling around on the bed and dry humping.
"Shoes were flying everywhere."
Hayley's hubby David was less than impressed.
“The morning David found out Michael had hooked up with his wife, Hayley, the night before, he was absolutely ropeable and he went and confronted him about it," another source told New Idea.
Coco Stedman and Cameron Dunne
Others who couldn't keep their hands off each other, despite being matched with other people in the 2021 season, were Coco and Cameron.
Fooling around on their respective partners, Samantha Harvey and Sam Carraro, didn't last long.
"Did Cameron hit it and quit it? He got his bowl of Coco Pops and then left for the day. He had his breakfast, he's out,' Coco said of the affair on the show.
"Maybe we both just hit it and quit it, mutual. There's no ill feelings there ... I couldn't keep it in my pants," she added.
Carolina Santos and Daniel Holmes
While this year also had a cheating couple, unusually, no-one found out during filming!
“None of us heard them talking at the dinner party or had any inkling about what was going on,” co-star Ella told the So Dramatic! podcast.
“We were all too involved in everything else that was going on.”
When the romance was finally revealed it shocked everyone, causing a walk out.
"We all came here for that reason, to meet some undeveloped feelings and fall in love and, obviously, the both of us didn't get that with who were initially matched with," Daniel said.
"We are genuine and real about this experiment and how we feel about each other.
"So yes, there's a part of us that would like to continue to experiment together."
But they have to do it out of the show as the experts would not let them stay.
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