Jennifer Lopez was treated to a surprise birthday party on a yacht on Tuesday (24Jul12) to celebrate her turning 43.

The singer/actress was blindfolded as her dancer boyfriend Casper Smart guided her onto the luxury Utopia II Superyacht in New York, where she was greeted by guests including her four-year-old twins Emme and Max, and her mother Guadalupe.

The birthday girl was photographed smiling in delight after she was presented with a large cake in the shape of a pink teddy adorned with the message, "Happy birthday BEAR!", in reference to the nickname Lopez shares with her toyboy beau.

Earlier that day, Smart tweeted his birthday wishes to Lopez, writing, "HAPPY BIRTHDAY TO THE MOST BEAUTIFUL BEAR IN THE WORLD!!!!!!!!!!!!!!! LOVE U.. @JLo."