VIDEO INTERVIEWS: Miley Cyrus and Liam Hemsworth Talk Romance and Hard Rock At Last Song Premiere

Miley Cyrus and Liam Hemsworth made their romance official on Thursday night as they walked the red carpet for their new film The Last Song. The young couple and their co-stars revealed details to RadarOnline.com about how their onset chemistry blossomed into offset love.     

VIDEO: Miley Cyrus Says She Loves Liam Hemsworth

"It's amazing," Miley said about striking romance gold during filming. She credited the film’s writer, who also brought the world that other amazing love story The Notebook, with setting the scene: “I think Nicholas Sparks is kinda the best at that. It was good, it was awesome.”

Walking the carpet shortly after Miley, Liam gushed about his leading lady and love. "Miley makes me laugh," he said, also calling her a "super cool chick." Recalling her penchant for hard rock, Liam added: “I’d come up to the makeup bus in the morning and she’d literally have hard core rock music playing at six in the morning. It's kinda crazy...It’s too early!”

Co-star Hallock Beals says everyone on the film's set could see there was real romance in the air. "I was Liam's roommate out there," he said. Thanks to his front row view of Liam and Miley, he knew the two had potential. "Even if they didn't know it, we kinda knew it was gonna happen."

When asked when the heat between the two star's began, co-star Carrie Malabre said it was instantaneous: "Pretty much from the get-go."

Melissa Ordway, who plays an ex of Liam's in the film, seconded Malabre and Beals' comments, calling Liam and Miley's chemisty "explosive."

Watch Miley and Liam fall in love yourself by catching The Last Song when it hits theaters on March 31.