A McDonald's customer recorded her interaction with an employee after she ordered a sugar-free drink that she said tasted like it had sugar in it.

The moment was captured in a viral video and uploaded to TikTok by user Kaleb Walker (@kalebwalkerc). It has been viewed over 3.7 million times.

In the clip, a woman argues with a McDonald's worker, who can be seen on camera in front of several drinks.

"You don't like the taste," the McDonald's worker is recorded saying.

She appears to be telling the woman that she ordered the drinks and will have to pay for them.

"Are you out of your mind?" the customer asks from behind the camera. "I'm telling you, there's sugar in there."

The worker fires back that she is not out of her mind. She also claims that she watched her co-worker make the drinks, and sugar was not used in them.

"I did not put sugar in them," the worker continues. "That's how they taste."

Eventually, the customer refuses to pay for the drinks, and the worker tells her to go get coffee somewhere else.

In the clip's description, the woman recording is described as a diabetic.

"I ordered no sugar and they put sugar and then lied to me when I'm a diabetic," it read.

A person with diabetes has difficulty producing insulin (or may not be able to produce any at all). This can result in hyperglycemia, when there is too much glucose circulating in a person's blood stream. This can be life threatening and or cause damage to the body's organs like the heart, blood vessels, nerves, kidneys, and eyes.

In the comments section, many were surprised that the customer did not know flavored coffee would taste sweet.

"Mam if you get flavored coffee, it's gonna taste sweet," user Asia wrote.

"Customers need to realize that SF syrups are still sweet..." another viewer added.

"Girl... artificial sweeteners are sweet," user NicJo.Bee commented. "It's in the name..."

According to McDonald's nutritional information, its iced coffees are typically flavored with syrups that do contain sugar.

For example, one pump of its French Vanilla syrup contains 30 calories and 5 grams of sugar. One pump of the store's Caramel syrup contains 30 calories and has 6 grams of sugar.

The Daily Dot reached out to McDonald's via email and Kaleb Walker by TikTok comment and direct message for more information.