Mr. Dai was enjoying vigorous sex with his wife when he heard a sudden crack. The pain started immediately, and it was excruciating. Mr. Dai had fractured his penis.

The unfortunate Guangxi-based gentleman was rushed to the hospital on April 8, where doctors found his penis swollen like an eggplant and bent at an odd angle, the New Zealand Herald reports. It was a classic case of penile fracture, an affliction that researchers say is “uncommon.”

You may be asking yourself: How can a dick break if it doesn’t have a bone? Most people who have encountered an erect penis know that, while a boner certainly feels bone-hard, it does not, in fact, contain a bone. But as Mr. Dai and a surprising amount of medical literature have shown, a penis doesn’t need a bone to break.

In a 2014 paper in Advances in Urology about the conditions that most often lead to a broken penis, a team of Brazilian scientists outlined the process by which it can break. Consider this cross section of a dick:

The two big bulges are the corpora cavernosa — latin for “cave-like bodies” — which is spongy tissue that’s densely threaded with blood vessels. When a penis gets hard, it’s because blood is rushing in to fill those caves. All that hot blood needs to be contained, however, and that’s where the fibrous envelope known as the tunica albuginea — a hardy sheath of connective tissue — comes in. This ensures the blood in a hard penis stays put. Until it doesn’t.

What happened to poor Mr. Dai is that his tunica albuginea ruptured, causing the loud popping sound. The blood rapidly spilled out — being mid-intercourse, his body was still channelling his blood toward his genitals — which is why he showed up at the hospital with a swollen, purple dick. Fortunately, doctors can suture the broken tunica albuginea during emergency surgery, and one Urology study pointed out that it doesn’t really matter how much time you spend freaking out before you get to the hospital — whether you get there ASAP or wait up to a week, recovery seems to be the same.

Fractured penises could look a lot like this eggplant.

Luckily, recovery usually also means full restoration of the ability to get a boner. But while it heals, having erections can be painful — that’s why some doctors recommend taking drugs like diazepam or stilboestrol to suppress unwanted ones; others, however, say that the pain usually prevents one from forming, anyway.

The Brazilian researchers did point out that there are ways that penile fractures can be avoided. They found that cowgirl-style, woman-on-top sex is the position that puts a penis at most risk of breaking, but more generally any position (or activity) that risks only partial entry of a dick into a thing can be dangerous.

In a recent interview with Broadly, Indiana University School of Public Health professor Debby Herbenick explained that “penile fracture is more likely to occur in sex positions in which the penis fully comes out of a partner’s body before going back in, with the risky moment being the re-entry into the vagina or anus or mouth.” Other researchers have pointed out that “vigorous masturbation” can also hurt a dick.

It’s not clear what position Mr. Dai was trying out that painful night, though we do know that, whatever it was, he was giving it all he had. Still, only he can answer what’s really the most important question about penis fracture: Was it worth it?