Heidi Klum and her husband Tom Kaulitz enjoyed a romantic getaway to celebrate their seventh wedding anniversary in St Barts. The supermodel, 53, took to Instagram on Monday to share a slew of snaps from their trip with their dog, Fritz. Heidi put on a racy display as she posed topless and shared a video stripping off before heading for a swim in the sea in just a thong bikini. In another snap, the model packed on the PDA with Tom, 36, as they sunbathed on a towel. Other photos showed Heidi being gifted a huge bouquet of red roses and excitedly posing in amongst red balloons. She captioned the post: 'No caption needed'. Heidi Klum and…