Marc Malkin

Gregg DeGuire/WireImage.com, Russian Look/ZUMA Press, Jeff Vespa/WireImage.com

Miley Cyrus may find herself going head-to-head—and foot-to-foot—with Will Smith at Sunday's Teen Choice Awards.

Here's the deal:

Cyrus and her best buddy Mandy Jiroux (aka M&M Cru) have been engaged in a months-long YouTube dance-off with actor-dancer Adam Sevani (above) and his Step Up 2 director, Jon M. Chu (or ACDC). Sunday marks the final round of the fancy footwork battle.

"Will Smith is so cool," 15-year-old Sevani tells me today during a break from rehearsals. "I did the Kids Choice Awards with him, and he was just so cool. I wanted to use him for our [Teen Choice] performance, but I don't know if he's gonna be here."

Even without Mr. Jiggy, Sevani promises that the five-minute dance-off (each team has two and a half minutes to show their stuff) will be "history" in the making.

Why? Well, they've got a pretty good track record...

For their YouTube performances, ACDC recruited megawatt stars to make cameos, including Lindsay Lohan, Adam Sandler, Chris Brown, Amanda Bynes, Elijah Kelly, Hairspray director-choreographer Adam Shankman and even Diana Ross.

For its part, M&M started the celebrity guests with stars from the first Step Up movie Channing Tatum and Jenna Dewan.

Come Sunday, anything—or anyone, for that matter—is possible. "They don't know what we're doing, and we don't know what they're doing," Sevani says. "They don't know what celebrities we're using, and we don't know which ones they're using."

A rather confident Sevani predicts, "We're going to just murder them—single-handedly!"

The winners, chosen by the audience, will take home one of the coveted surfboards.

Depending on how you look at it, Cyrus may or may not have an advantage over the guys because she's also going to be hosting the awards show. "I'm hosting alone," Cyrus told me earlier this week, "so I'm kind of nervous."

In the end, Sevani says, the dance-off is nothing more than a fun and friendly competition. "I want her crew to do good and the same with mine," he says. "I want everything to be good, so I can be like, 'Wow, that was amazing. We need more of that!' "