You may want to put down your snack, because this is about to get gross.

A woman went into a McDonald's in Cambridge, UK and came out with a viral video. Sounds great, right? Of course it's not. Didn't you read the title?

She found maggots, and lots of them.

Twitter user Isabella shared her disgusting experience on Wednesday, and it's accrued over 43,000 views so far. Her video shows the transparent spout of a ketchup dispenser with lots of tiny yellowish blobs in it. It looks weird at a glance, but then you realize they're moving.

Never going near the ketchup in @McDonalds again. For those of you who can’t tell, these are MAGGOTS 🤢🤮 pic.twitter.com/7B3khnDwME

— Isabella 🌹 (@bellaritchie00) October 3, 2018

Isabella followed up several times in the comments of her initial tweet, adding that she was ignored by staff, who continued serving customers when she informed them, and had to stop another customer from eating the ketchup because they weren't aware.

She eventually got to speak to a manager and emailed the company about the issue, but the damage is done. How many customers ate the contaminated ketchup before Isabella noticed the maggots? They must have been in there for at least a day or so, right? How infrequently do those dispensers get cleaned?

So many questions, so little time. McDonald's is launching an investigation, according to their response on Twitter, but we doubt we'll ever know the results.

Hi Isabella, we have found your friend's email to our Customer Services team and they are picking this up directly and launching the investigation. Should you require any further assistance from us or have any further questions, please send us a DM.

— McDonald's UK (@McDonaldsUK) October 4, 2018

If you've ever worked in fast food, help us out. Does this kind of thing happen often behind the scenes? If so, we're never eating out again.