YUKON, Okla. (WNCN) — An Oklahoma chemistry teacher is behind bars after deputies discovered she was having sex with one of her students.

Hunter Day, 22, was arrested after deputies pretended to be the boy arriving at her home for another sexual encounter.

“This is a classic case of a serious breach of public trust. School teachers are entrusted to protect and educate our children, not to engage in an unlawful sexual relationship with them,” said Chris West, Canadian County Sheriff, in a news release.

The boy’s parents went to the Canadian County Sheriff’s Office after searching their boy’s phone.

“The parents told investigators they had already been through the phone and discovered text messages and nude photographs, and were concerned Day had already had sex with their son,” the Sheriff’s Office wrote. “They were also extremely concerned because they believed Day was their son’s Chemistry teacher.”

Investigators determined the two had in fact already had sex, deputies said.

They also learned that the two were planning to meet at Day’s residence Wednesday afternoon for another tryst, authorities said.

“Investigators using the boy’s cell phone contacted Day acting as if they were him, and asked if the meeting was still on,” deputies wrote. “Day replied ‘yes,’ and indicated that he should hurry up and get there before her husband got home from work.”

At the scene, deputies posing as they boy texted that they had arrived. Day responded that the front door was unlocked, deputies said.

“Investigators opened the door and found Day sitting on the living room floor with the lights turned off, candles lit, and wearing a T-shirt and workout shorts,” deputies wrote.

Day told deputies she had a sexual relationship with the boy, that she had sent him pictures of herself in her underwear and had received pictures of his genitalia.

Day was charged with rape in the second degree, possession of child pornography and soliciting sex from a minor using technology. She was to the Canadian County jail, and her bond was set at $85,000.

“I’m no longer surprised by the people who commit these crimes, because predators come from all walks of life,” West said.