Jennifer Lopez and Extra host Mario Lopez worked the flashbulbs while celebrating the grand opening of Planet Dailies and Mixology101 at The Grove Thursday night.

The American Idol judge's gunmetal grey dress is stunning. Mario's see-thru shirt isn't bad, either!

Those at the party got to see an exclusive viewing of JLo's newest video for "Dance Again" ... featuring her sexy young beau, Casper Smart. Watch the entire video below.