What a cork-block.

A Serbian woman was left incontinent after putting a cork in her vagina during a sex game — and then leaving it in for a shocking 3½ years.

A case study detailing the freak accident was published recently in the journal of “Pediatric and Adolescent Gynecology.”

The wince-worthy incident occurred after the unnamed 19-year-old inserted the stopper from a bottle of hairspray in a “state of impaired judgment during sexual intercourse,” per the report.

After an initial attempt to uncork herself was unsuccessful, the gal decided to leave the foreign body in place.

She had refrained from going to the hospital for so long “due to her sense of shame and fear of judgment from the environment,” according to the study.

The backed-up Belgrade resident didn’t seek medical attention until for nearly four years when she lost control of her bladder.

The obstruction apparently didn’t impede her menstrual cycles, which were occurring regularly and at normal intensity.

When she arrived at a doctor’s office, medics noted that the vaginal tissue around the cork was heavily swollen.

Medical personnel proceeded to extract the cork from the teen using “standard gynecological instruments” — but she wasn’t out of the woods yet.

After inserting a urinary catheter, medics finally pinpointed the source of her incontinence: She reportedly had a hole between her bladder and the vaginal wall — known as the vesicovaginal fistula in medical parlance — which was causing urine to seep out.

It was not clear whether the tear was caused by the cork itself, but the patient was “referred to adult urologists for further diagnosis and treatment,” per the study.

Speaking of unlikely items in unusual orifices, a French hospital had to be partially evacuated last year after a senior citizen arrived with a World War I artillery shell lodged in his rectum.

The patient had inserted the weapon of mass obstruction during a botched attempt at sexual gratification.