Police in Chicago say a man who caught another man in bed with his girlfriend decided to teach him a "lesson" by setting his balls on fire.

According to the official police report, the unidentified suspect arrived at his girlfriend's apartment Monday afternoon to find her and the victim in flagrante delicto.

The attacker then knocked his rival unconscious and pulled out a Bic lighter, which the police say was set on "high."

"This will be a lesson to you, I lit your [genitals] on fire," the suspected reportedly told the still-unconscious victim.

Officers were called to a nearby laundromat, where they found the victim rubbing Vaseline on his burns.

He was subsequently transported to the burn unit at the University of Chicago Hospital following a brief stay at Holy Cross Hospital.

The Chicago Tribune reports that none of the parties involved were taken into custody.

[H/T: Opposing Views, photo via Shutterstock]