While dancing at a bar or night club, a girl inexplicably reaches her hand down a guys pants and starts to get him off. Similar to the better known DFMO (Dance Floor Make-Out), but a much bolder move. Clearly communicates the girl's intentions and avoids any ambiguity. While jerk off traditionally means to get off oneself, its usage here is synonymous with hand job for phonetic purposes of the acronym.
No man, I was pretty hammered. But I think he scored a dfjo with a girl at a bar downtown.