The man's pose has nothing to do with the activity he was engaged in before dying, according to a volcanologist who studies the Pompeii victims.
"The individual in the photo is an adult man, killed by the hot pyroclastic surge (hot gas and ash cloud which killed most of the population living around Mount Vesuvius), with both arms and legs flexed due to the heat," Pier Paolo Petrone told the Daily Dot.
Petrone told the Daily Dot that “most of the human victims found in Pompeii often show ‘strange’ position of arms and legs, due to the contraction of limbs as a consequence of the heat effect on their bodies after death occurred.”
But even without a masturbatory caption, people couldn't help but imagine something else going on in the photo. "I'm sure he had a good eruption before the end," said one commenter on Instagram.