A perverted and rare sex act where a girl reaches in to her vagina while a man already has his penis inserted and gives him a handjob. Similar to the cunt jackula and rarely seen outside of mexican bordellos or with very enthusiastic porn stars. This act requires that the womans vagina be very dilated and her fingernails be cut fairly short.
James knew that Susan was a bit of a whore but he never expected her to try and fist herself while he was fucking her. He was even more surprised when she started to give him a handjob when he was already balls deep. She called it a turfucken and claimed she had invented it. He would later update his facebook letting everyone know how much he enjoyed it, and that he also passed all his finals so could finally graduate. Too bad he now had $80,000 in debt and no job prospects in this economy.