Jennifer Lopez was spotted at several Vegas hotspots yesterday before taking the stage with Enrique Iglesias at Mandalay Bay.

OK! NEWS: JENNIFER LOPEZ ISN'T INTO BAD BOYS: "I LIKE THE GOOD GUYS... THEY HAVE TO BE SWEET"

J.Lo was first seen lounging poolside with boyfriend Casper Smart at MGM Grand's Wet Republic. She showed up around 3 p.m., strutting her stuff in a white midriff-baring outfit by Bec & Bridge and carrying a white Birkin bag. Observers say that Casper never left J.Lo's side. She graciously waved and interacted with her fans, and snacked on french fries, fruit and non-alcoholic pina coladas. Also spotted at Wet Republic: Prince Harry and King of Queens star Leah Remini.

OK! NEWS: JENNIFER LOPEZ FILES $20 MILLION LAWSUIT AGAINST FORMER DRIVER

Later, Jennifer walked the carpet as host of an event at Pure Nightclub in Ceaser's Palace Hotel & Casino.