A customer's worst nightmare came true when a South Carolina McDonald's employee allegedly spit into cups of iced tea that were returned by the customers since they were not sweet enough.

The sickening event took place when a mother and a daughter visited McDonald's on Main Street over the weekend and picked up two iced teas from the drive-through, according to Associated Press.

They gave back the drinks since they thought they were not sweet enough. After tasting the new drinks offered to them, they felt the tea needed still more sugar so they decided to add sugar at home. Only after they opened the lid to add sugar, did they find large bits of phlegm floating on the drink.

The duo immediately took pictures of the drinks and called the police. The incident was further confirmed when the surveillance camera footage showed 19-year-old Marvin Washington Jr. leaning down over the cups. Washington was arrested on Wednesday and charged with malicious tampering with food. He was released from jail on $5,000 bond, Fox news reported.

Meanwhile, the owner of Mcdonald's, where the incident reportedly happened, has asked the public to withhold judgment before coming to any conclusions about the quality of food served at his restaurant, LA Times reported.

Nothing is more important to me than the safety and well-being of my customers, the franchise operator, John Kennedy, said in a statement released to The Times.

I want to assure my customers that my restaurant has the most stringent food safety and quality standards and I caution anyone from reaching a conclusion without the facts. As this is a pending police matter, it would be inappropriate to discuss further and, as such, any additional questions can be directed to the police department, he added.

Chris Morran, deputy editor of Consumerist.com, the consumer news and advocacy blog operated by Consumer Reports said that the incident reminds us that we walk into these restaurants at their mercy.

Morran also told The Times that most people working in the restaurants are nice and hard-working people and that was remarkable considering the treatment they receive from customers and the management. He also said that this particular incident was a classic move by an irritated employee.