Last year, Ken Yerdon and his wife, Julie Aluzzo-Yerdon, went to a local Chili's restaurant in Clay, N.Y., for a meal. When the food arrived, the couple noticed that it was undercooked and complained to their server, Gregory Lamica, then 24, adding that the chips they had ordered had not yet been served. Even though their meal wasn't what they were hoping for, the couple left a generous tip, reported ABC News.

"They were polite to the server and even left a tip," said Robert Lahm, the Yerdon's attorney.

"We weren't rude or anything," said Yerdon. "It was a busy night, but we didn't expect for our food to get spit in."

"We were patient with him, but we could tell he was annoyed with us," Aluzzo-Yerdon told Syracuse.com.

"All Ken said to him was, 'Are you OK? Have we done something to offend you?' And he said, 'Oh, no, no.'"

Before leaving Chili's, the Yerdons ordered drinks to go. As they drove off, the lid of the Styrofoam cup came off and, when Ken looked inside, he was shocked and disgusted by what he saw.

"The lid popped off and I looked in, and there was some spit in the cup," said Yerdon. "It wasn't regular spit either. It was definitely a loogie."

Yerdon then dropped off his wife and son before going back to the restaurant to speak to the manager. When he told the manager about the incident, he apologized and gave Ken a refund and some coupons. However, the manager refused to admit that Lamica was responsible for the incident, said Lahm, according to the Inquisitr.

A few days after the incident, the Yerdons contacted police authorities, who then questioned Lamica. He denied the incident, but allowed investigators to take a swab from his mouth for a DNA analysis. The test results arrived many months later, confirming that it was indeed Lamica's spit in the drink.

Lamica was found guilty of disorderly conduct and sentenced to a one-year conditional discharge and a $125 surcharge. The Yerdons filed a lawsuit on Tuesday against Lamica and the owners of the Chili's franchise, accusing them of negligence and retention of an incompetent employee.