Lopez rocked the red carpet Sunday night in a black Anthony Vaccarello gown, which bared her left arm and featured a very high slit that put her right leg on display. "This is on the cusp of pushing the limits," E!'s Ryan Seacrest warned. "They were concerned about flesh, they sent out a memo to artists."
Lopez, whose most famous fashion moment happened at the Grammy's twelve years ago in 2000, feigned ignorance to the guidelines. "They didn't say anything about leg! I thought I was being such a good girl!"Related: Katy Perry's plunging dressMorgan Lopez writes for Yahoo! Music