Miley Cyrus' costar (and real-life boyfriend) talks about their new romantic movie and competing with his brother for Marvel's ''Thor'' movie

By John Young
Updated March 26, 2010 at 04:00 AM EDT

Brotherly Competition
Before scoring the part of Miley Cyrus’ beau in The Last Song (opening March 31), Hemsworth, 20, auditioned for summer 2011’s superhero flick Thor — only to watch his 26-year-old brother, Chris (who played James Kirk’s dad in Star Trek), snatch the title role. Any bitterness? Nah. ”At the end of the day, one of us is playing Thor!” says Liam.

Life’s a Beach
In The Last Song, Hemsworth plays a beach volleyball champ, but though the actor’s a born-and-bred Aussie, he had zero experience with the sport. ”I lied to the producers,” he says, ”and when I turned up to practice, I was really, really bad.” Complicating matters was the sweltering heat on the Georgia shoot last summer. ”The sand was too hot to stand on,” he says, ”so we wore wet-suit bootees, and they just cheated our feet out of the shots.”

I Heart Miley
At this year’s Oscars, Cyrus confirmed that she’s dating Hemsworth. ”It was kind of impossible not to get close during that movie,” the actor admits. ”She’s got one of the biggest hearts.”

Up Next
Hemsworth is set to star in the 3-D action epic Arabian Nights.