Ok I watched Kelly's performance again and I retract my previous statement that she was lipsynching. Kelly was singing live! If you look at the part where Trey Songz comes back out and she says "sing it y'all," you can see the imprint of a wireless microphone package (or whatever you call the thing you hook to the back of your clothes) through her jacket. Also when she rips off her shirt and she and Trey are hugged up at the very end, if you look closely you can actually see the wireless mic taped to her chest. I'm done. Chick slayyyyed!