Parodies, once a cheaply filmed niche segment of the adult movie market, are big business these days filled with expensive special effects, real story lines, actors who can (sometimes) actually act and costumes that even comic-book geeks find authentic.
The movies may also help save an industry looking to rebound from years of Internet piracy, illegal downloads and amateur videos that have caused a serious financial hit, said Mark Kernes, senior editor at Adult Video News. The business has gone from annual revenues of as much as $12 billion a few years ago to about $7 billion today.
"We certainly do have a problem with piracy ... and sadly no one seems to be able to do anything about it," said Kernes.
But now Superman is coming to the rescue, along with Batman, Iron Man and Spider-Man.
All four have taken star turns in full-length, slickly produced films that include hard-core crime fighting and, well, other hard-core scenes although milder versions were made of some of the same films.
Neither the makers of the mainstream movies nor comic book writer and Iron Man creator Stan Lee wanted to comment. A person who answered the phone at Lee's office said he doubted Lee had heard of the parodies, and then hung up. Lee, himself, didn't respond to an email.
Marvel Comics also did not respond to requests for comment. Warner Bros.' DC Entertainment Division, which makes the Superman and Batman films, had no comment, said spokeswoman Courtney Simmons.
Since the trend toward superhero parodies began three years ago, no porn company making them has been sued. For years the courts have ruled that parodies, like other forms of speech, are protected by the First Amendment.
"Mainstream porn, from a copyright protection, from a First Amendment protection, is essentially the same as any other form of written expression," said entertainment lawyer David Ginsburg, who is executive director of the UCLA School of Law's entertainment, media and intellectual property law program.
"The rules of parody apply as equally to porn as they do to any other form of parody, like 'Saturday Night Live' or Mad Magazine," he said.
The porn parody superhero revolution seems to have begun in earnest around 2010, when veteran adult film director Axel Braun, who boasts of having a collection of DC and Marvel comics dating to his childhood, brought his "Batman XXX" film to Vivid Entertainment Group.
The company's chief executive, Steven Hirsch, initially wasn't that impressed. But when the film became the biggest-selling and renting video of the year, Hirsch said, he quickly realized there was a core demographic his business was overlooking: comic-book geeks.
Soon Vivid was cranking out four to six of the movies a year, timing their release to whenever the mainstream films hit theaters.
Other companies soon followed with their own releases, including: "The Justice League Of Porn Star Heroes" and a parody of the vampire television series "True Blood."
Production costs can be more than 10 times as high as making a traditional pornographic movie, but the parodies sell for three times as much, Braun said.
They are, Hirsch said, the best-selling movies on Vivid TV, "after our celebrity sex tapes."