It's watching people have sex in public places, whilst pretending to walk your dog....it was in the news over here not long ago as a former footballer, Stan Collymore, admitted to doing it.
referring to a sexual position (which I thought was a strange thing to ban). Ha ha ha. I've never heard the term, either.
That's the true harbinger of spring, not crocuses or swallows returning to Capistrano, but the sound of a bat on the ball ~ Bill Veeck