Jennifer Lopez and Casper Smart got down and dirty with each other on New Year's Eve.
The American Idol judge and the 24-year backup dancer spent the weekend in Miami Beach, according to People, starting the party on Thursday night at nightclub Amnesia.
"They were very sexy with each other, dancing and bouncing around and making out," a witness says, adding that the pair hung out until 3 a.m. "They couldn't help but attract attention, although Jennifer was trying to lie low from onlookers."
Marc Anthony is reportedly steamed over J. Lo's romance with Smart, even threatening to take away custody of her children, but another source says Lopez looked "very happy" at the hot spot.
She and Smart are hotter than ever, in fact, as insiders confirm they went out on a yacht Friday afternoon, while J. Lo went shopping with her daughter on Saturday afternoon.
The couple stayed at a private residence all weekend and rang in 2012 at the Soho Beach House with friends.
Take that, Marc!
[Photos: Pacific Coast News]