AceShowbiz -

Jennifer Lopez took a break from her tour with Enrique Iglesias to celebrate her 43th birthday. Her dancer boyfriend Casper Smart threw a surprise party for the singer on a yacht docking in a harbour in uptown Manhattan. He covered her eyes with a scarf when they arrived at the spot.

J.Lo wore a red Tom Ford zipper dress that clung to her body and revealed her bare back with a chunky gold fastener resting at her hip. Casper donned black slacks, a black shirt and a maroon blazer. He completed his dapper look with thick-framed glasses.

The former "American Idol" judge, who was born on July 24, 1969, looked genuinely surprised when Casper uncovered her eyes. The yacht was decorated with black and white balloons and was crowded with guests supposedly comprising of family and close friends.

Earlier in the day, the couple had lunch at Buddy's Restaurant in Manhattan. J.Lo ran into Jessica Alba and the two actresses exchanged a warm hug. Jessica was there with her own family and didn't join the birthday girl at her table.

When he didn't escort his girlfriend in town, Casper helped preparing the party. At one point, he was seen telling the event planner where to put a large picture of her girlfriend as a little girl. A teddy bear birthday cake with "Happy Birthday BEAR!" message was spotted carried into the yacht by some workers.