Gisele Bundchen is planning to star in a steamy calendar as a birthday surprise for her boyfriend. The Brazilian supermodel, who is currently dating American football star Tom Brady, is set to pose in sexy lingerie and don a New England Patriots shirt to celebrate Tom turning 31 on August 3.

Supermodel Gisele Bündchen bares her bottom, and her soul, on the cover for the July issue of GQ magazine. The Victoria's Secret model also reveals why she hasn't made it to the alter.

Brazilian supermodel Gisele Bundchen earned more than million last year, making her the top-earning model in the business. The beauty topped the list of Forbes.com's 2008 World's Top-Earning Models.