In the first group were husband and wife duos Steph and Gian and Kyle and Leslie, and sisters Eliza and Liberty.
Over the past two months, we've watched as Kristy and Brett, and to a lesser extent Leah and Ash, have targeted the other three groups, accusing them of getting 'special treatment' and breaking the rules. Kristy and Brett even admitted to deliberately attempting to 'sabotage' Steph and Gian's work.
But the other teams had no idea how divided the worksite was until they watched the season alongside the rest of Australia, and now, it seems the biggest alliance on The Block could be over.
On Sunday night's room reveal episode, Kristy went so far that even Leah wasn't prepared to back her up publicly.
The drama all began when sisters Eliza and Liberty won the Kitchen and Laundry room reveal, after revealing they had a 'secret gnome' that gave them one extra point.
Despite the fact the sisters would have won even without the gnome, Kristy and Brett (who placed second on the night) refused to even congratulate them.
The couple then put on heinous MAGA-style 'Make The Block Great Again' hats and said during a piece to camera that they "weren't surprised" Eliza and Liberty had been given an extra point.
In their piece to camera, Ash said he "doesn't have a problem with it" while Leah said "I do" before claiming the sisters "look guilty".
Later, the teams sat down together and Eliza and Liberty explained they won the 'secret gnome' during the breakdancing challenge and they weren't allowed to tell any of the other teams.
"No conspiracy theories — I know there's chat about that," Eliza added.
That's when things heated up between the contestants.
"We were really happy that you got a 10. We walked out of our interview saying 'we're really happy that they got a 10, they deserved it, and I'm happy that they won'," Kristy said to the sisters.
"The gnome thing was definitely something that we were like 'of course it is' but are we saying that you do get an extra hand? 100 per cent," she added.
"What, I'm kind to people, so they're kind back to me? Yeah, special treatment," replied Eliza.
"Definitely not the case, Eliza, so calm down," Kristy shot back.
"Everyone gets little things—" Eliza tried to say before Kristy interrupted her.
"We DON'T, WE DON'T GET THINGS. You firsthand said that if you just hold a bag of installation, Nine and Six [The Block's builders] will come and do it for you," Kristy said. "Your words, not ours."
"Well, good thing it's all on camera," Eliza replied.
"I just feel like you're in no position to be giving us direction when you're getting stuff done for you," Kristy said before the teams went their separate ways.
House 2 and House 3 left together and drove back to the worksite. In the car, Kristy lamented the fact that no one backed her up, including Leah.
"I tried to hold my tongue but I soon as I saw that nobody was actually going to fucking hold account for what everybody has been saying," she said.
"I'm with you by association!" Leah replied, clearly frustrated.
"You don't have to be," Kristy shot back, before adding, "I'm not here to make friends."
It seems this moment is just the beginning of the fracturing of Leah and Ash and Kristy and Brett's friendship and alliance on The Block.
In the promo for this week's episodes, Leah is seen telling Eliza and Liberty that she and Ash do not believe the same "conspiracy theories" that Kristy and Brett do.
Later in the promo, Leah and Kristy have a heated argument and then Leah tells Brett: "Your wife is dead to me". One thing's for sure, it looks like we're in for plenty more drama.
The Block continues at 7:30pm tonight on Channel Nine and 9Now.