Sex outside marriage, and sex that occurs under out-of-the-norm circumstances, may increase the risk of penile fractures, said study researcher said Dr. Andrew Kramer, a urologist at the University of Maryland Medical Center.

The heightened risk appears to be due to the unconventional situations, and consequently, locations, surrounding sexual acts, the researchers said.

Men in the study who had suffered penis fractures commonly were having sex in unusual settings, including in restrooms or at work, when the injury occurred. The majority were having extramarital affairs.

In such atypical situations, sex may be rushed and involve unusual or awkward sexual positions, Kramer said.