One Direction attended the premiere for their 3-D flick, "One Direction: This Is Us," Tuesday night in London. And even though [article id="1712699"]Zayn Malik's engagement[/article] to Little Mix's Perrie Edwards caused lots of buzz at the fete, fans still want to know how all-access the August 30 flick really is.

"The toilet scenes were a little bit awkward, but apart from that it was good," Harry Styles dished to MTV U.K., with Malik adding, "I think the thing is when it's 3-D, it's like a massive camera. It's a bit different, but you just try and think of it as a normal camera and then whatever."

It's a big week for the fellas of 1D. After performing at the Staples Center and taking home three Moonmen at the 2012 VMAs, the guys are slated to make an appearance at the 2013 MTV Video Music Awards where they are up for Best Song of the Summer for their upbeat single, "Best Song Ever."

Until Sunday's VMAs, they will just be making the rounds spreading the word about their Morgan Spurlock-directed doc, out next week. And while the guys have never been shy about letting fans into their world, this movie takes it to the next level.

Liam Payne said, "That was one of the main things, really. The movie's kind of here to show a different side of us and a few things they might now know. It is a movie for you to know a bit more.

Louis Tomlinson added that filming was only annoying "sometimes in the morning... where sometimes you'd be a bit groggy."

And while everyone puts a lot of themselves into the movie, Niall Horan bares a bit of skin as well.

"That's what I do. They go all access, all areas, I guess," he said. "It's weird seeing ourselves in 3-D, I guess. It's weird watching yourself back and hearing stuff that you say and you might regret it, but the whole world's gonna see it and you might not want them to see it, but there it is."

1D will be one of the many A-listers at the VMAs on Sunday, August 25. Lady Gaga, Katy Perry, Kanye West and more are all slated to take the stage at Brooklyn's Barclays Center when the show goes live at 9 p.m. ET/PT.