It's the Not Much Material Girl. Madonna sunbathes in a skimpy bikini while taking a romantic cruise with hubby Guy Ritchie.

　　The singer, who was 43 on Thursday, decided to celebrate by taking to the water with 32-year-old Guy in Miami.

　　Madonna showed off her fabulous figure in a skimpy blue and green bikini - topped off with a large floppy sun hat.

　　Film director Guy relaxed in a T-shirt and baseball cap as he sipped a glass of Guinness.

　　The night before devoted Guy interrupted his wife's concert in Miami to present her with a huge surprise birthday cake.

　　The audience joined in with her dancers to serenade the Queen of Pop with a resounding chorus of Happy Birthday.