By accident, I stumbled on this Urban Dictionary entry this morning:
758. the-Zwicky: A sexual maneuver where you are getting blown, and as you are about to cum, pull out, stick your dick in her ear and jiz. When she screams, you quickly haul back and dick slap her across the forehead to shut her up.
“Dude, I pulled the Zwicky on a chick last night, and now she’s got an ear infection (by Zwicks Aug 31, 2004)
Clearly a made-up gross-out entry by someone named Zwick or Zwicky. There are four other equally unpleasant entries contributed by this guy.
For the record, I disassociate myself from any such sexual practice, with woman, man, or beast.