A Minnesota teenager had to have his testicle amputated after being punched in the groin by a classmate, KARE11.com reported Friday.

David Gibbons, 14, was changing classes in his Crosby, Minn. high school when he was attacked by another student playing a game called “sack tapping.”

David’s mother, Christy Gibbons, said it wasn’t until hours later that they realized something was wrong.

"One o'clock in the morning he woke me up and told me he was in excruciating pain," she said.

David was taken to St. Joseph's Hospital in Brainerd, Minn. where surgeons removed his right testicle.

And David is not the only student who has suffered the consequences of the “sack tapping” game.

"It's just gotten way out of control," said Dr. Scott Wheeler, a urologist in Brainerd, Minn. who says he performs three to four surgeries a year on boys with ruptured testicles and other complications as a result of “sack tapping.”

"All parents, you need to have this talk with your kids not to do it. It's lost its humor. It's not a game anymore. People get hurt," he added.