Chris Rock, expect some angry feedback from teen-pop fans.

"Are you ready for some real lip-synching?" the 1999 MTV Video Music Awards host asked by way of introducing Britney Spears and 'N Sync, who, it was revealed on Wednesday's "Total Request Live," had planned to share the VMA stage (see [article id="1432541"]"'N Sync, Britney Teaming Up For VMA Performance"[/article]). Unfortunately, Spears and 'N Sync wound up sharing the stage for just the briefest of moments... though more eagle-eyed fans might have spotted 'N Sync sooner than others.

The Metropolitan Opera House stage was decked out in a high-school play approximation of a classroom, and Spears' outfit -- a tight, spangly black and silver midriff-baring shirt and pants that were barely hanging on to her hips -- would probably get her sent home from most secondary learning institutions.

After dancing and pouting along to a somewhat choppily remixed version of her hit "Baby One More Time," she teased that she was going to bring out a few friends. At first, those friends appeared to be only her backup dancers.

However, 'N Sync soon emerged onto the set, revealing that they had been sitting in desks toward the rear of the stage the entire time. Replacing Britney's sparkle and glitter with grit, the guys were dressed in grubby, sporty high-school gear.

J.C. delivered an energetic solo turn during 'N Sync's performance of its breakthrough hit "Tearin' Up My Heart," but unfortunately for the group's fans, 'N Sync's time on stage seemed to be over as soon as it started.

Adding insult to injury, Rock asked, "Why did they even have mics on?" after the dual performance.

Catch all the sizzlin', star-packed VMA action direct from Miami on August 28. MTV News' preshow kicks things off at 6:30 p.m. ET/PT, followed by big show at 8 p.m.

Vote for the Viewer's Choice Award, see a timeline of MTV Video Music Awards history, and relive highlights of last year's event. And for more MTV Video Music Awards news, check out the MTV News VMA archive.