(Noun) -- a term used for an object or idea used to cause someone who's attracted to someone else to force their object of affection to talk to them. It often comes in the form of something being left with the romantically attractive person in question.
Entymology: The term "stolen bicycle" refers to the late 1990s/early 2000s Japanese cartoon program "Pokemon". In the show's early episodes, the main character, Ash, stole the lead female character's (Misty) bicycle. Later, she claimed to only be following him around on his journey until she gave her the "stolen bicycle" back. The real reason however, was that she was romantically attracted to Ash, and the "stolen bicycle" just gave her an excuse to follow him around.
Bill: "I left my Calculus book on that hot Jenny girl's desk. She walked off with it, so it looks like she'll be talking to me sometime soon..."
Rick: "Ohhhh... the old stolen bicycle trick. Gotcha."