WOODSTOCK, Ill. (CBS) — A 34-year-old teacher has been charged with sexting with one of the students at the Des Plaines middle school where he taught.

McHenry County Sheriff Keith Nygren announced Thursday that Jack Pickup, 34, of Barrington, stands charged with felony grooming and misdemeanor sexual exploitation of a child. He was arrested after the parents of a 15-year-old former student of Pickup’s found out that he had been sending her explicit texts and instant messages.

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Pickup had been a teacher at Chippewa Middle School in Des Plaines, where he’d met the girl when she was in 7th grade, sheriff’s police said.

Pickup began an inappropriate online relationship with the girl last year, and kept texting with the girl after she graduated 8th grade, police said. He also gave the girl his number so they could stay in touch, police said.

Late last month, police discovered that Pickup had been sexting with the girl, and had sent her a picture of his penis. Police intercepted the explicit texts, and gathered information so they could arrest him on the spot at his parents’ home in Barrington.

Police praised the girl’s parents for taking action.

“The parents of this victim should be commended for monitoring their child’s online and texting conversations. We encourage parents to maintain vigilance and continue to remind their children of the possible dangers of social media,” McHenry County Undersheriff Andrew Zinke said in a news release.

Pickup is being held at the McHenry County Jail, and was scheduled for a bond hearing later Thursday.