PHILADELPHIA — Demi Lovato and Miley Cyrus met on the set of "Hannah Montana" six years ago, long before they became two of the biggest names in pop music. Now, they're competitors at the 2013 Video Music Awards, and despite their very different lifestyles (Demi isn't much of a twerker), Lovato thinks their friendship will last.

"She knows how I feel about the whole partying thing," Lovato told MTV News. "I love her to death and I'm always like, 'Just be careful' and she's like, 'Dude, I'm chilling. It's fine.' But I care for her so much that I'm so protective, but she's good. She's got a good head on her shoulders."

Lovato and Cyrus are facing off in the Best Female Video category at the VMAs. Demi is nominated for her emotional power-pop hit "Heart Attack," while Miley is up for her laid-back party anthem

"I think it's great," Demi said about her friend's latest hit. "I think it's a good song... It's a song a lot of people have fun to and if people are enjoying it, then great."

Just last year, Lovato told MTV News that she steers clear of the partying scene, saying, "I'm crazy with my hair... it's my only form of rebellion, I don't drink, I don't do drugs, I don't party." Cyrus, meanwhile, has been open about her image.

Despite their differences, Lovato said she would "absolutely" be down for a collaboration, only if there isn't any twerking involved.

"She's twerking and she looks amazing doing it," Lovato said of ...

About a decade before "Blurred Lines" became a runaway hit for Robin Thicke, he was just a man on a bike in his "When I Get You Alone" video, looking very different than he does now.

The video featured Thicke playing a bike messenger, dressed casually in a baggy T-shirt and jeans and, most importantly, rocking an incredibly thicke, uncontrollable mane of hair as he careens through the city streets, making all sorts of stops and deliveries. The look is a far cry from the clean-cut, suited-up style the chart-topper rocks these days. So, what does he think about that era now?

"That hair is like its own llama," he joked to MTV News about his hairstyle in the classic clip off his 2003 album A Beautiful World. "It's like wearing a llama around!" he added.

In the years since, Thicke has trimmed his locks, tailored his clothes and found other ways to make his videos unforgettable. Most recently, that included chilling with T.I. and Pharrell, as well as beautiful models in various states of undress, in his , which was just nominated for three Moonmen for the 2013 Video Music Awards.

Thicke may have found a way to top that hairstyle and the nude ladies for his next video for "We're gonna have to see if President Obama will be in it," he shared about finding another way to keep his videos fresh after the viral smash that is "Blurred Lines" and the recently rediscovered "When I Get You Alone."

"I don't know how you can top 'Blurred ...

SAN DIEGO — Joss Whedon could have escaped Comic-Con a hero simply by taking the stage in Hall H on Saturday and announcing the title of his next Marvel flick,

But on Sunday at the Con, the director decided to pull back the curtain on his plans for the superhero sequel during a chat with Marvel LIVE, and for that we salute him.

"Age of Ultron," he revealed, will start shooting in London at the end February or the beginning of March (ahead of the film's summer 2015 release date). Read on for the rest of the news Whedon revealed about the film.

'Age of Ultron' Will Not Be Based on 'Age of Ultron
"Age of Ultron," a recent Marvel event penned by Brian Michael Bendis, shot up the Amazon sales chart after Saturday's announcement. Those eager buyers might have acted a bit too swiftly.

"[That's] not the case," Whedon said of basing the movie on the book. "We're doing our own version of the origin story of Ultron....We were crafting our own version of it where [Ultron's] own origin comes more directly from the Avengers were already know about."

Hank Pym Isn't Involved
Since a) an movie is in the works, b) Ant-Man is a creator of one version of the robot Ultron, and c) Hank Pym is one alter-ego of Ant-Man, many people assumed Pym would play a role in Whedon's "Age of Ultron." Not true, said Whedon.

"The other thing is in the origin story there was Hank Pim, so a lot of people assumed he was going ...

SAN DIEGO — Chloe Moretz went out of her way to explain that she's nothing like Hit Girl during the panel at San Diego Comic-Con. In an exclusive clip from the new movie scene — which debuted on MTV and MTV2's "Guy Code Honors" — Hit Girl goes out of her way to emphasize she's no sidekick.

"Robin sucks!" declares Moretz, as Hit Girl alter-ego Mindy Macready. Kick-Ass, played once again by Aaron Taylor-Johnson, has just tried to convince Mindy to unite with him as a Batman and Robin style crime-fighting dynamic duo.

Hit Girl points out that her skill level puts her in the NFL of teenaged vigilantes, while Kick-Ass is still playing in the pee-wee leagues. Kick-Ass knows she's right and begs her to pass along some of her knowledge. He's ready to be the padawan to her Jedi Master. She smiles. "And you'll do anything I say?" she smirks. Kick-Ass enthusiastically consents.

Cut to Hit Girl slapping Kick-Ass around, easily dodging his one measly punch, then handily placing him on the exercise room floor via a series of super-rad kicks. Check out the clip to see the verbal and literal sparring between the pair.

At their Comic-Con panel on Friday (July 19), Moretz described what attracted her to characters like Hit Girl and the title character in the forthcoming "Carrie" remake. "It's really about finding those characters who are opposite of who I am as a person, because I'm such a normal 16-year-old girl," she said to the Hall H crowd, via satellite from Boston.

She went on ...

SAN DIEGO — Now that you've had time to watch the new trailer again (and again...and again) without hyperventilating, it's time to take a closer look at all of the brand-new footage revealed when it debuted at San Diego Comic-Con on Saturday.

While the film's first trailer focused on Hunger Games victor Katniss Everdeen's new position as a beacon of hope for the citizens of Panem oppressed by the Capitol, the second one is much more explicit about the civil unrest in the country. The first movie was about Katniss fighting for her life in the Games, but this one highlights Katniss fighting for Panem and against the Capitol. "Remember who the real enemy is," Katniss' mentor, Haymitch, tells her toward the end of the footage.

Instead of simply alluding to the Quarter Quell — the special version of the Hunger Games that will bring back Katniss and Peeta to compete against victors from other districts — the new trailer shows President Snow explaining the twist. The Capitol is trying to quell a rebellion, but it's clear now (even if you haven't read the book) that this movie is about much more than another Hunger Games.

Here are a few more key scenes from the trailer that have us especially excited about the Nov. 22 release.

Meet Finnick Odair
The first footage of Katniss' biggest ally in the Quarter Quell arena was probably the most anticipated reveal. Unfortunately, all we saw was Finnick's sly smile before the tribute parade. Fortunately, he was shirtless. Now that we've seen Sam Claflin's toned torso, will ...

SAN DIEGO — Comic-Con is filled with fans dressed as Jedis, super villains, zombies, mutants and more. But here's a philosophical question to ponder: if you've played a Marvel hero in several movies, does it count as cosplay?

Tom Hiddleston stormed the stage in character as Loki (take that, Andrew Garfield!) on Saturday during Marvel's much-anticipated Hall H panel. The Asgardian god of mischief and adopted half-brother of Thor, set to return in November's provided the appropriate amount of theatrical fanfare for the studio's big announcements. (Sales of the story collection shot-up online following the announcement of the title).

MTV News caught-up with Hiddelston shortly after the panel wrapped. Unfortunately for us, he had already changed. "I should give this interview in costume," he joked. "Actually, that would have been quite fun, twiddling my mustache, in costume. That would be so weird! With all the rig on. Can you imagine?"

It's quite easy to imagine, actually, given the level of excellence the 32-year-old English actor brought to his performance at the panel. "It was a hoot! As my mum would say, it was 'a hoot,'" he said of the experience. He said the plan was initially outlined to him by Marvel Studios boss Kevin Feige, via phone call about two weeks ago.

"I was a bit blown away by it. But I was onboard from the get-go," he explained. "It was just a question of fine-tuning it. It was really fun working with him on the details of what it should be. I really wanted ...