It did flop ...Around The author definitely had their reasons for picking "How the codpiece flopped" instead of "How the codpiece went out of fashion" Also,

It did flop ...Around The author definitely had their reasons for picking "How the codpiece flopped" instead of "How the codpiece went out of fashion" Also, judging from the URL, they must've been pretty happy to find the joke because the title used to be "what happened to the codpiece"