Jennifer Lopez sizzled on the red carpet at the Grammy Awards Sunday night, showing some serious leg in a black one-shoulder Anthony Vaccarello dress that left her right leg entirely exposed -- all the way up to her hip.

The singer, on hand to present an award with rapper Pitbull, joined a host of music's biggest stars on music's biggest night at the Staples Center in Los Angeles for the 55th annual awards ceremony.

Last week CBS, which aired the Grammys, sent out a memo requesting that stars not show too much skin this year. The notice asked specifically that "buttocks and female breasts" (apparently male breasts were okay) be "adequately covered."

The net also asked that see-through outfits and visible thongs be avoided. They also told stars not to expose any part of their "genital regions" in the letter.

Most stars followed the rules, while a few -- like J. Lo and Katy Perry -- pushed the boundaries while keeping in good taste.

J. Lo joked about her attire while presenting, saying, "As you can see, I got the memo."

Her presenting parnter, Pitbull, replied, "You inspired the memo!"

The former American Idol judge's dress reminded us of the one Angelina Jolie wore to the Oscars last year, prompting the term "Jolie-ing" for women who put one leg out on display.