Rogue groin? When filming a 'Star Wars' movie went kind of NSFW

Moviemaking is rarely quite as glamorous as it's cracked up to be -- even when we're talking about Star Wars moviemaking.

That much was evident to Diego Luna, who plays Captain Cassian Andor in the forthcoming Rogue One: A Star Wars Story, once he started working with Alan Tudyk, who plays the droid K-2SO.

You see, although on the screen K-2 is a 7-foot-1 droid made entirely of computer graphics, Tudyk was on set in all those scenes. This was so the other actors, primarily Luna, would have someone to act against.

But because Tudyk is not 7-foot-1 -- he's a mere six-footer -- he had to wear stilts on the set, along with a rather tight-fitting costume for CGI-mapping purposes. And that in turn meant -- well, let's let Luna tell the story.

"The first month, we just couldn’t look at [Tudyk] because he did look ridiculous," Luna told a conference of Star Wars journalists earlier this week. "It was the tightest pajamas ever. Because he had these stilts, you were always the height of his balls. It was quite intimidating!"

That's right -- every time Cassian Andor looks up at K-2 during Rogue One, it means Luna is trying his damnedest not to think about the fact that his eyes are level with Tudyk's nether region.

Give that man an Oscar.

After the conference, we asked Tudyk to confirm the story -- which he gladly did. "He was level with my balls, yeah," Tudyk told Mashable. "That was not an exaggeration."

And if one of your first thoughts is "how did he go to the bathroom?" the answer is, with great difficulty.

"Taking off the stilts was a pain in the ass," Tudyk said -- so he just went as he was. "It made going to the restroom difficult. Aiming was an issue. No one wanted to be next to you. Also I could see over all the stalls."

So if you were in Pinewood studios last year, answering the call of nature, and you were suddenly horrified to see a guy in tight pajamas on stilts staring down at your cubicle -- now you know.

Perhaps Tudyk's intimidating position had some influence on another fact we learned: that he got to ad-lib quite a few of his lines.

You may have seen the Rogue One clip released last week in which K-2 is concerned that Jyn Erso has acquired a weapon and is trying to explain this concern to Andor. (The two are both seated, luckily for Luna.)

As written, the line went "would you like to know the odds of her using that weapon on you?" But it was Tudyk who added, after a beat, the laugh line: "really high!"

We also asked Tudyk to explain why all droids in the Empire -- well, himself and C-3PO -- seem to have English accents. "He has an accent because people in the upper ranks of the Empire had English accents," Tudyk explained. "We tried to make it consistent."

Still, the American actor thoroughly enjoyed putting the voice on. "I always thought the English could get away with saying things that are so blunt ... but the accent takes the edge off so you don't feel it as an insult," he says.

"K-2 doesn't go out of his way to insult anyone, but if he doesn't like you, he'll let you know."

For Luna's sake, we hope that doesn't involve any crotch-grabbing.