In the long list of things to never do—stick a fork in a socket, dangle a baby from a balcony, wear sandals with socks—tattooing your penis is probably pretty high on that list. But a 21-year-old Iranian man didn’t heed the laws of common sense, and he was punished with a perpetual erection. The unnamed man had “borow be salaamat,” which means “good luck with your journeys” and his girlfriend’s initial “M” tattooed on his penis. In the weeks that followed, he experienced pain, resulting in an inability to get an erection, but after eight weeks, he noticed his nighttime erections started lasting longer. Eventually, his penis stayed in a permanent, semi-rigid state. According to a study by doctors at the Kermanshah University of Medical Sciences in Iran that was published in the Journal of Sexual Medicine, they believe the tattoo needle “penetrated the penis too deep, creating an arteriovenous fistula.” He was diagnosed with nonischemic priapism, which is caused by blood being unable to leave the penis. He attempted to have a shunt implanted to drain the blood, but the procedure was unsuccessful. The doctors wrote, “Because of the painless nature of erections, moderately good preservation of erectile function during intercourses, and disappointment with former surgery, the patient has declined to undergo further therapies, and lives with his condition.” And in case you still weren’t convinced that a penis tattoo is a bad idea, they added, “Based on our unique case, we discourage penile tattooing.”