Jennifer Lopez and Casper Smart were hand in hand leaving her birthday lunch at Bubby's NYC today. J Lo's continuing her 43rd birthday festivities after starting last night. J Lo wore leather pants to a pre-big-day dinner at Cipriani with Casper yesterday. She's having fun in the Big Apple — and meanwhile, we are celebrating with a look at Jennifer's hottest moments! Another year isn't the only thing Jennifer has to celebrate. She recently kicked off the US leg of her 2012 world tour and will premiere her new video "Goin' In" tomorrow on MTV.