A former Miami University professor has admitted arranging for sex last year with someone he was told was a 14-year-old girl and faces up to 30 years in prison, court documents say.

Kevin Armitage, who resigned shortly before being indicted, pleaded guilty this week in federal court in Missouri to traveling across state lines to engage in illicit sexual conduct. The girl was actually an undercover FBI agent.

Armitage, 53, was a “senior” member of a website, usasexguide.nl, according to court documents, that allows members to give accounts of their sexual encounters with prostitutes.

The documents say Armitage made 576 postings under his user name – “CletusTheYokel” – detailing experiences with prostitutes in places including Ohio, Arizona and Tijuana.

In May 2018, a federal investigator who was monitoring the site, posted that he could provide a phone number for a young prostitute. The post was titled, “Young Spinner.”

According to documents filed as part of his guilty plea, Armitage responded: “Is what I live for. Id love the number and will treat her right.”

The investigator gave Armitage the phone number for the undercover FBI agent, telling him that she was “super young.”

Soon after, on May 24, 2018, Armitage contacted the undercover agent. He said he was traveling to the Kansas City area and discussed days he could meet for sex.

Early in the conversation, court documents say, the agent told Armitage she was 14 years old. He asked for a photo, and the agent sent him one of a supposed 14 year old.

Armitage agreed to meet with her on May 30, 2018.

The day before, Armitage and the undercover agent discussed additional specifics. He first would have to meet her cousin at a restaurant in Kansas City, Missouri.

“Show her ur condoms, money, flash her a smile, buy me a milkshake, and get (expletive),” the agent texted. “Best day ever.”

“Sounds good,” Armitage replied. “What flavor milkshake?”

On May 30, Armitage met with another undercover agent who posed as the cousin. She asked him if he knew the girl was 14. He said he didn’t know, then asked her to text him the address so he could “go there.”

They agreed on $100. Armitage, with a condom in his pocket, ordered a milkshake to go, court documents say.

He was arrested soon after. He is scheduled to be sentenced on Aug. 15.

Armitage, who had been living in Oxford, was a professor of individualized studies.

His Kansas City-based attorney, Chris Angles, declined to comment.