McDonald's Spit Tea.

It's not on the fast food chain's traditional menu, but until Thursday, you were able to find it at a single location in Simpsonville, South Carolina. A mother and daughter did -- and then they called police.

Officers have since arrested and charged Marvin Washington, Jr. with unlawful and malicious tampering with food. He allegedly spit in the duo's sweet tea.

The two women did not originally order McDonald's spit tea. They had asked for sweet tea, but when they took a sip, they realized there was no sweetness to be had. They returned the drinks, according to WYFF-TV, and were given new ones. The tea still wasn't sweet.

Instead of waiting, the mother and daughter went home where they planned to add their own sweetener. But when they took off the lids, the station reports they found large chunks of phlegm floating on top.

Once notified, investigators hightailed it over to the McDonald's and took a look at security footage. As Sheriff Deputy Laura Campbell told WSPA-TV, the video seems to show Marvin Washington spitting into the cup:

Though Washington's actions seem relatively minor, contaminating food with bodily fluids is dangerous. Meningitis, mononucleosis and some forms of the herpes virus can be transmitted through saliva. Common colds and influenza are also easily transferred via spit. It's a major health and safety issue.

For this reason, McDonald's spit tea carries with it a prison term of up to 20 years. But if Marvin Washington is currently disease-free, the judge will probably sentence him to far less.