Jennifer Lopez and Casper Smart at Nightclub Opening

J Lo and Casper Sizzle in Sin City at a Nightclub Opening

J Lo and Casper Sizzle in Sin City at a Nightclub Opening

Jennifer Lopez and Casper Smart made a stylish appearance at Hakkasan Nightclub's grand opening at the MGM Grand in Las Vegas on Saturday. Jennifer stunned in a clingy little black dress while her boyfriend rocked a bright red blazer on the carpet. Inside the club, the duo mingled with Vanessa Hudgens, her boyfriend, Austin Butler, and dancer Cheryl Burke, while other celebrity attendees like Glee's Mark Salling, birthday boy Pharrell Williams, and Paris Hilton spent the night listening to Calvin Harris DJ the event.

Over the weekend, J Lo had more than just Sin City fun on her mind since her son, Max Anthony, got stitches for a minor chin injury while in LA with dad Marc Anthony. J Lo addressed the situation on the red carpet, saying, "Of course I was freaking out, but he was fine. He said it tickled." Back on the work front, J Lo is prepping to launch her next single, "Live It Up," with Pit Bull on May 8. In addition to new music, J Lo may be returning to TV after rumors surfaced earlier this month that she'll return to American Idol's judging panel as a replacement for Mariah Carey. Producers have denied the replacement assumptions, but no comments have been made regarding whether Jennifer will return to the show next season.