Be careful with your erections.

In a video now gone viral, retired professional basketball player Dennis Rodman explains how a sex stunt gone wrong broke his penis. Later, it happened again. And another time after that.

Not everyone has the misfortune of breaking his penis three times. In fact, most who experience the injury take great precaution not to let it happen again. But it’s understandable that if it happens once, it could happen again. And that’s due to the fact that the activity most likely to break your boner is one almost everyone enjoys: sex.

We’ve all heard stories about sex gone wrong. TLC produced an entire documentary series on the subject. But penile fractures relate to sex in a special kind of way, and that’s because they only occur when erections are present.

The penis contains three cylindrical tubes. The smallest one, located on the underside of the penis, is the urethra. The two larger tubes, known as the “corporal bodies,” are the ones responsible for erections. When a man becomes aroused, these areas fill with blood. If the penis is forcefully bent when engorged, that lining can rip. And that’s how one lands a penile fracture, a painful and dramatic injury often accompanied by an audible “pop,” and if he's really unlucky, some blood.

A 2015 study published in Advances in Urology revealed that, during sex, the "woman on top" position is the most likely to result in a penile fracture.

"Our hypothesis is that when woman is on top she usually controls the movement with her entire body weight landing on the erect penis, not being able to interrupt it when the penis suffers a wrong way penetration, because the harm is usually minor in woman with no pain but major in the penis,” the authors explain.

"On the contrary, when the man is controlling the movement, he has better chances of stopping the penetration energy in response to the pain related to the penis harm, minimizing it."

Doggy-style was found to be the second riskiest position, with 29 percent of afflictions resulting from the stunt. “Male on top” was responsible for just 21 percent of fractures. Out of 42 cases, 28 occurred during heterosexual sex. The average age of injury was 34 years old.

There are, however, other ways to sustain a penile fracture. In Japan, the majority of cases are attributed to masturbation and rolling over in bed onto an erect penis. Most cases in the Mediterranean are the result of patients snapping their penises in order to rid themselves of erections. In Iran, a good majority of cases root back to self-manipulation. Others have been known to offer up excuses that are, in all likelihood, bogus. Donkey bites and falling bricks are among the more colorful explanations.

Fortunately, it’s not all that common of an injury. Since 1924, "1,600 cases have been recorded worldwide." It is possible, however, that many incidents of penile fracture go unreported due to the amount of embarrassment that can accompany the injury.

Those who undergo an unexpected initiation into this group should prepare for the following.

You will lose your erection, almost immediately. After the break, which most often occurs at the base of the penis, the area will start to swell and fill with blood. And it’s going to hurt. The discoloration may extend into the surrounding flesh. Urologists call this “eggplant deformity.” Once you arrive at the hospital, doctors can confirm the fracture through a clinical exam, and in more extreme cases, by tests like an urethrogram, MRI scan or X-ray of the penis.

Emergency surgery is often performed in order to relieve the hematoma (the blood collecting outside the vessels) and repair the damaged tissue. Then, it’s time to ice. Patients are typically instructed to refrain from sex for up to six weeks. Many will prescribe anti-androgens to prevent the occurrence of erections, which could complicate the healing process.

The good news? Almost all patients make a full recovery. So keep on thrusting, but please, try not to miss your target.