A disgruntled former employee is going viral for revealing some of the allegedly dark “McMysteries of McDonald’s.”

TikToker Georgia Zacki is boldly declaring that she knows why the McFlurry machine always seems to be on the fritz — as well as why you should “never” order fries at the iconic fast food chain.

Zacki — a UK-based content creator who boasts nearly 11,000 followers on TikTok — is claiming to reveal the not-so-tasty secrets of popular McD’s food products in a now-viral video that’s racked up 4 million views as of Monday morning.

The young woman claims she worked for the legendary global chain for about a year and that there are a few simple reasons the milkshake machine doesn’t work — and it’s not because it’s chronically broken, she claims in the clip.

”And it’s not cause we’ve run out, that’s a lie,” she said. She went on to reveal that the ice cream machine isn’t in use because one, if it’s too busy — employees will “just turn it off.”

”Two, there’s no one to do it,” Zacki added. ”Three, we can’t be bothered to go get mix.” She also claimed that the machine could be dirty, and there could not be enough mix-ins for the milkshakes.

Among the other secrets the former employee dropped: why customers should never order the fries.

Zacki alleged that when handling the crispy side dish, hungry workers stick their hands in the gigantic pile and munch from the stack.

”We do eat the chips. If you’re ordering fries, someone’s probably had their hand in — not in your fries — but in the fries,” she said. “If you go up to the counter and say that we didn’t give you something, like fries, burger, whatever, we probably won’t check.”

The Post has reached out to McDonald’s reps for comment about the viral TIkTok claims.

Meanwhile, it’s probably a good idea to be nice to your servers, as employees will talk about you behind your back if you’re rude — bestowing nasty nicknames onto customers.

Zacki pointed out: ”If you’re going through the drive-through and you’re a knobhead, the person that is taking your order will tell everyone else in the store before he comes to the window that you’re a d – – k.”

In a note to her followers in the comments section, Zacki wrote: ”I would like to say don’t comment on Maccies workers until you’ve had a Big Mac thrown at your head for being out of BBQ sauce.”

Other ex workers of the fast food place gave their two cents about the company, chiming in with their own experiences.

“Our machine was genuinely broken if we said it was the managers in my store would not of let us not sell because we can’t be arsed to get mix lol,” one person recalled.

Another penned: “Honestly mate whatever you have to do to make a service job easier. Do it. Turn off that machine. It’s 99p they’ll cope 🥰.”

“I left 2 months ago, they literally don’t care about your staff. like they only hire school kids then moan when they are going to do exams,” someone said.