Over the course of 17 movies (with more on the way) and nine TV series (with more on the way), the Marvel Cinematic Universe (MCU) has had its fair share of violent explosions and swearing, all mostly with a PG-13 bent. But when it comes to nudity, the farthest the Filmic House of Ideas has pushed the envelope is by taking shirtless hot dudes and spraying them down with alien goo.

Yep, Marvel has mostly limited themselves to the decolletage of chiseled Chrises -- until this past month's The Punisher. Ben Barnes, in his star turn as Billy Russo, finally broke the barrier by giving thirsty Twitter fans full -- well, not frontal, but a close second. In the interest of, uh, science (or maybe history? Let's say history), take a brief look back through all the times Marvel superheroes have lost their briefs.

Iron Man (2008)

Nudity: None

I'm including this on the list just for the sake of historical accuracy, as the 2008 Robert Downey, Jr. starrer launched the Marvel Cinematic Universe. Prior to this, the rights to Marvel and its stable of characters were spread over various studios (and the X-Men and Fantastic Four movies still reside at Fox, while other rights like those to Spider-Man's supporting characters and even The Hulk are best described as, "it's complicated"), while Iron Man was an attempt to truly create an interconnected series of films and -- eventually -- TV shows.

It also set the tone with its PG-13 rating due to "some intense sequences of sci-fi action and violence, and brief suggestive content." Though Downey Jr.'s Tony Stark is a playboy, and jokes about sleeping with models, other than some skimpy costumes this is still a movie that (ostensibly) was looking to attract families as well as older fans.

Thor (2011)

Nudity: A glimpsed buttocks

Chris Hemsworth's turn as the God of Hammers (sorry, God of Thunder) has provided plenty of ab-errific shirtless scenes in the MCU, but only a scant corner of a buttock. Once Thor has been exiled to Earth in the movie, he's taken to a hospital and treated as a mental patient. On trying to escape, the once God gets injected with some sort of knockout drug in order to put him down, and we briefly get a peek of Hems' worthiness.

Thor: The Dark World (2013)

Nudity: A pixelated penis

For a series about an alien planet called Asgard, they sure aren't doing a good job of guarding their a--es. The second Thor flick featured a brief scene of recurring player Erik Selvig (Stellan Skarsgard) running naked through Stonehenge with an instrument (scientific, ya perv) in order to find portals to another world. Since we saw the footage on a "news" report, though, Selvig's pants area was appropriately pixelated.

Guardians of the Galaxy (2014)

Nudity: Of the raccoon variety

Technically, Rocket Raccoon (Bradley Cooper) isn't a raccoon; or at least over the course of two movies, we don't find out what the cranky space creature is, exactly. But after being sent to an alien prison, he's stripped naked, sprayed with orange stuff, and we get to see his furry CGI behind as his teammate Peter Quill (Chris Pratt) glimpses some disturbing looking cybernetic implants in his back. I'm including this to be a completist, but you'd really have to think that, say, there's something sexy about Donald Duck not wearing pants in order to consider this envelope pushing nudity.

Daredevil, Season 1 (2015)

Nudity: MTV Movie Award worthy side-boob

Though Agents of S.H.I.E.L.D. officially moved the MCU to the small screen, both that show, and Agent Carter were on ABC -- and a broadcast, family-friendly network usually won't show more than underwear clad actors tumbling into bed, followed by a tasteful fade to black. Then there's Daredevil, which launched the subset Marvel/Netflix series of shows. They technically are in the same universe as the movies (and ABC shows), but skew much darker, and more adult. Because of that, you can see the vaunted side-boob nudity from actress Deborah Ann Woll (who plays faithful office assistant Karen Page on the show) as early as the first episode of season 1. Later shows would take things further, but someone had to get there first.

Jessica Jones (2015)

Nudity: Not as much as you remember

When Marvel dropped Jessica Jones, the show was immediately lauded, not only for its thoughtful and powerful take on sexual assault through the lens of superpowers, but being one of the few shows on TV (comic book based or otherwise) with realistic sex scenes. Messy, fun, and powered by the characters, JJ definitely broke ground (and at least one bed) when it comes to sexual content. Despite the raunchiness of the scenes, most of it was hidden by sheets or clothing. Yes, there's a simulated oral sex scene and the aforementioned bed smashing sex between Jessica (Krysten Ritter) and Luke Cage (Mike Colter). But aside from a half revealed buttocks spotted by Jessica as she spies on a cheating husband from far away in the first episode, there's no nudity.

For real. Seriously. Like, I know you think you saw Mike Colter's exposed rear, but you didn't. Aside from some back nudity and very realistic thrusting, nothing else is revealed. Sorry, fellow scientist/historians.

Daredevil, Season 2 (2016)

Nudity: Peak TV

The second season of Netflix's series about a blind vigilante with superpowers introduced his ex-girlfriend, Elektra (Elodie Yung). Both in the past and present, Elektra and Daredevil's civilian identity, Matt Murdock (Charlie Cox), had a twisted affair -- which led to a slight step up on steaminess on screen, as well. In the fifth episode, during a sex scene, we see both back nudity and side-boob, which is enough to turn anyone to the dark side.

Luke Cage (2016)

Nudity: Almost

Luke Cage picks up where Jessica Jones left off, both literally in terms of plot, with Luke heading uptown to heal his broken body and heart, and figuratively in terms of sexy sex times. The first episode has an extremely graphic-by-Marvel-standards sex scene, including some groping and ye olde side boob. Later in the premiere, some of the characters visit a strip club, which, not that surprisingly, is filled with strippers. They're wearing thongs and pasties, though, so while the costumes don't leave a lot to the imagination, they're also not nude.

Thor: Ragnarok (2017)

Nudity: Hulk butt

By mere weeks, the third Thor movie delivered the first official nudity in the Marvel Cinematic Universe; but even here that comes with an ass-terisk. In a scene set on the alien planet Sakaar, the jolly green giant The Hulk (Mark Ruffalo) emerges from a hot tub completely naked, showing off his other jolly green giant to his buddy Thor. The son of Odin gets the full monty, while the audience sees Hulk from behind. Meaning we get to see his butt. Except, and here's the caveats: we only see the top half, the bottom is cut off because of the framing; and in case you haven't noticed, he's an enormous, green, CGI-ed monster. So while some would give Ragnarok the record, we're saving that for our next (and final) entry.

The Punisher (2017)

Nudity: *extremely tina belcher voice* butts

No asterisk required for this one: The Punisher finally, 100% breaks the nudity barrier for the Marvel Cinematic Universe. In the fifth episode of the show, after a sex scene, Ben Barnes gets up to use the toilet and you're -- what's the opposite of punished? -- rewarded with a shot of his posterior, in full view of the camera. Not CGI. Not half cut off due to framing. Not pixelated, or part of a raccoon: a real, human butt (and yes, it's his butt). The sex scenes are also far more graphic than anything glimpsed in Luke Cage or Jessica Jones, upping the ante to FX levels, which is definitely an official scientific scale and not something I just invented.

Where the MCU goes from here is anyone's guess... Will the second season of Defenders take place at a nudist colony? We won't find out until that show gets green lit (though probably not). Until then, we'll see you in the history butts. I mean books.

The Punisher is now streaming on Netflix.