Kellan Lutz showed us Twihards that chiseled chest we've all come to love over the past few years while enjoying a shirtless beach day with his girlfriend Sharni Vinson in Miami, Fla., yesterday. OK! GALLERY: KELLAN LUTZ AND GIRLFRIEND SHARNI VINSON GO BOATING DOWN UNDER  The hunk was all smiles as he hung out with his lady, even tossing her around in the water before working on his tan. Read More >>