Kristin Cavallari threw on an interesting bathing suit yesterday to pose during Miami's Swim Fashion Week on behalf of Skyy and Diesel. She gamely posed for a photo op in a pool, then headed inside the Raleigh Hotel to walk during Diesel's show. To take the edge off, Kristin tweeted, "Hair and makeup time . . . [the catwalk]'s getting closer! Definitely having a glass of champagne before I walk the runway." There have been plenty of Kristin Cavallari bikini sightings in the last few months, since she announced her engagement to NFL player Jay Cutler. Jay left his football duties temporarily, so that he could be with Kristin in Florida to offer his support as she works.