Just a few days ago, someone I know had to be hospitalized because of somehow slipping and smashing badly into their desk while doing normal, boring office work. From how it was described to me, I cannot help thinking sex was somehow involved, like receiving or giving oral sex from under the table maybe.
EDIT: Typing this, I was reminded of a guy who got smacked in the back of his head. Got X-rayed, everything looked normal. They kept him in the hospital for observation, though. X-ray again after an hour, a huge hematoma had evolved under his skin, pressing on the upper spine. They immediately drained it. Otherwise, it would have killed him very quickly.