Once in a while, controversial things happen in comic books. Wonder Woman killed Maxwell Lord to save Superman and Batman. The Joker tortured Barbara Gordon, and Batman kills a whole bunch of people. More recently, over at Marvel, Captain America was announced as being a secret agent of Hydra.

While they serve a creative purpose, these narrative developments are, by their very nature divisive, with consequences and ramifications echoing through respective series for extended periods of time. Thus far, live-action cinema adaptations of comic book stories have largely avoided the most contentious plot points – but that’s all about to change with the release of Suicide Squad.

Clearly, in a film that depicts events from the perspective of a team of supervillains, there are going to be some controversial aspects to the storyline – but it is the presence of Harley Quinn and The Joker that really kicks this dubious tale into high gear. Suicide Squad will be the first time these two lovebirds have had their romance laid bare on the big screen and, indeed, marks the feature film debut of Harley herself. But, just why is this particular liaison so hotly debated?