Who watches Watchmen? Plenty of people, at least according to box office estimates indicating the new movie about a group of flawed superheroes grossed a solid $55.7 million over the weekend.

But it’s a good bet that many of those viewers had their eyes on one Watchman in particular: Dr. Manhattan, an otherworldly blue being who spends much of the movie completely naked, and whose genitals are often clearly visible.

The character’s nudity, and ample endowment, are already the subject of plenty of chatter.

“Someone asked me how much of Dr. Manhattan is you,” said Billy Crudup, the actor who was the basis for the primarily computer-generated character, on The Daily Show.

Crudup then held up his thumb and forefinger several inches apart, and added, “About that much.”

Manhattan’s matter-of-fact nudity is a perfect expression of the character: He was once human, but evolved beyond that after an accident with an “Intrinsic Field Separator.”

The superhero's new state of being allows him to experience time in a non-linear fashion, and to understand the universe on a quantum level. Being privy to such wisdom, he has grown gradually indifferent to many human concerns, like clothing.

What's unusual is that Zack Snyder chose to feature the nudity so prominently. Even today, few American movies feature frontal male nudity. And let's not forget Watchmen is a major studio release with a budget near $130 million.

The rules are different for female nudity in American films, of course: women are frequently naked – even the few women in superhero movies. Rebecca Romijn's Mystique showed something pretty close to full frontal nudity in the X-Men movies.

Still, perhaps it's not surprising that Watchmen is pushing the envelope. It's a pointedly different kind of superhero movie—grittier, more explicit, both in its violence and sexuality. In the U.S., the film is rated R.

Another male superhero, Patrick Wilson's Nite Owl, is also seen frontally naked in Watchmen, though that shot isn’t nearly as explicit as the scenes of Dr. Manhattan.

The film is an extremely faithful adaptation of its source material, Watchmen, a series of equally gritty comic books. Dr. Manhattan’s nudity is portrayed in the same matter-of-fact way as the comics.

What accounts for Watchmen going where even few American art house movies have gone before? The change is probably attributable to three things: Snyder, Watchmen comic-book creator Alan Moore, and Americans growing comfort male nudity.

Moore is a true visionary, renowned not only for this influential series, but other titles including V for Vendetta and From Hell. He's known for taking on adult themes in an uncompromising style, and Dr. Manhattan’s complete nudity started with him—lthough even he wasn't sure his publisher would approve, and the artist made a point of keeping the nudity tasteful.

“I was careful to give him understated genitals, like a piece of classical sculpture, too,” original Watchmen artist Dave Gibbons told SequentialTart.com in 1999. “I'm sure some people didn't even notice he was nude for a page or two and, by then, it was too late!”

Meanwhile, Synder was also the director of 2006’s 300, another R-rated graphic-novel adaptation. Snyder pushed boundaries in that film’s portrayal of violence and homoeroticism (while some found it to be homophobic, as well).

"Keeping [Watchmen] R-rated wasn't so easy," Snyder told the Los Angeles Daily News. "After 300 came out, they were more like, 'Would you be open to discussing PG-13?' I talked about it, but I knew what was appropriate for the movie."

And while we're still far from full nudity equality, Americans – including American men – are no longer as uncomfortable with the objectification of the male form as they were even a few years ago.

Most Americans have grown accustomed to seeing David Beckham’s bulging crotch peering at them from Times Square or the pages of a magazine. And he’s hardly the only celebrity using his body in the same way that many female celebrities have long done.

Are we finally becoming a nation that's less uptight about male nudity? It's a big leap to that from a single, movie that features a naked computer-generated superhero.

But Watchmen might be a sign that things are moving in the right direction.