12-Packing Heat! Fashion Designer Marc Jacobs & Ex-Boyfriend Show Off Washboard Abs

By Leah Ornstein - RadarOnline.com Style & Beauty Editor

Ab-solutely fabulous hunks in trunks!

Looks like Marc Jacobs and his former flame Lorenzo Martone have figured out that two 6-packs double the heat on the beach!

The couple, who publicly split in 2010, were reunited in St. Barts on Tuesday, stripping down and showing off their fabulous physiques in skintight swim shorts – and RadarOnline.com has the photos.

The celebrated fashion designer proudly revealed his collection of quirky body art (including a SpongeBob SquarePants tattoo) in dark spandex swim shorts as the two strolled down the shoreline of the luxe Caribbean vacation spot, while Martone, who briefly dated ‘N Sync star Lance Bass after splitting from Jacobs, showed off his godly body in a more revealing red, white and blue striped style.

Though it is not clear whether or not the duo is back together, they looked extremely animated and happy throughout the afternoon as they engaged in beach activities with their pals.