Liam Hemsworth's girlfriend Miley Cyrus makes him "very happy".

The actor recalled meeting the Hannah Montana star on the set of 2010 movie The Last Song and said it was not possible to resist their mutual attraction.

The couple have been dating on and off since 2009 and are often spotted looking loved-up or partying together.

"She makes me really happy. When you start, you want to be professional, but when you're filming those scenes with someone and pretending to love them, you're not human if you don't feel something," Liam told US publication Details.

The Australian heartthrob also spoke about the showbiz industry in general.

The Hunger Games actor described Hollywood life as surreal and explained his laid-back childhood helps him to stay grounded.

"We grew up surfing and stuff, that's why we can laugh. This business is ridiculous," Liam said.