'It's a Petri dish!': Horrifying photo proves why you should always check the hotel coffee machine

The internet is collectively gagging after a photo of a horrifying hotel coffee maker went viral.

The stomach-churning snap was shared on Reddit by a user called Henry River on Monday, who captioned it, “And this is why you check the hotel coffeemaker before you use it....”

It’s unclear which hotel is responsible and when the photo was taken, but regardless, fellow Redditors were disgusted.

“Jerk, why'd you tell me that? GIVE MY BACK MY IGNORANT BLISS!” wrote one.

“It's like a Petri dish!” remarked another.

“Well excuse me while I retroactively gag for every single cup of coffee I’ve made in my past 20 years traveling,” admitted one, to which Henry replied, “So sorry, dude”.

What is that in the coffee machine?

People can’t decide what exactly is growing/dying/decomposing in the water reservoir at the back of the machine.

Several Reddit users were convinced that a previous guest had attempted to cook food in there.

One suggested that it’s “mac n cheese” while another suggested “chicken vertebrae”.

“What is that? Half a biscuit floating?” asked one.

A coffee machine savvy Redditor jumped in to clear up any confusion, writing, “The white object is the tube that sends the hot water to the coffee filter. All of the other debris is mould, fungus, etc”.

Well, at least we know now.

Hotel of horrors

The discussion didn’t end there, with users airing some very, very dirty laundry from their own horror hotel stays.

“My friend found dirty diapers in the hotel ice container the other day,” shared one Reddit user.

“Everything in every hotel is filthy and everything in a hotel room has a coating of dried human fluids on it. If you can imagine it, some deviant has already done it a few times in your room,” attested another, adding that their ‘sources’ were a motel maintenance man and a hotel concierge.

A “business traveler” piped up to reveal the two things they always check after they check-in: “the coffee pot and ice bucket”.

“Your example of the coffee pot is exactly why I check,” they explained, adding, “I have also heard a story from a hotel worker about a guest who pissed in the coffee pot AND the water container of the iron. A guest tried to iron his shirt and noticed something was wrong. Shirt was ruined from ironing piss onto it.

“People should also realise that the ice buckets are used all the time as puke buckets for drunken guests. If you plan on using one be sure to clean it out very good and always use the plastic bag insert,” they advised.

Thanks for the tip!

Got a story tip or just want to get in touch? Email us at lifestyle.tips@verizonmedia.com

Want more lifestyle and celebrity news? Follow Yahoo Lifestyle on Facebook, Twitter and Instagram.

Or sign up to our daily newsletter here.