I Am Number Four star Alex Pettyfer showed off his sculpted abs on the beach in Miami yesterday. His open shirt gives us a peek at the sexy six-pack he also put on display during a recent appearance on the Ellen DeGeneres show. He's currently out promoting his movie with girlfriend Dianna Agron and there are reports that the two are engaged. Dianna and Alex's reps have both played coy about the rumors, though sources close to both have confirmed the exciting news. Their film I Am Number Four comes out in two weeks, so we'll be hearing a lot more from Alex and Dianna in coming weeks as they enjoy the promotional train.