London couple Mojgan Azari and Omid Amidi-Mazaheri should have kept their sadomasochistic tendencies in the bedroom.

Everyone hates dentists, and here’s another reason why—Azari allowed her boyfriend to work on 600 of her patients, which wouldn’t be so bad if he were actually a dentist too. Amidi-Mazaheri drilled patients without anesthesia and inserted fillings that crumbled in patients’ mouths.

Some like it rough—but not that rough.