Liam Hemsworth reportedly gets ''concerned'' about girlfriend Miley Cyrus.

The 'Hunger Games' actor is said to look ''embarrassed for her'' on some occasions while she is out in Los Angeles clubs, although insiders believe he loves her ''fun-loving side''.

A source told Us Weekly: ''She gets pretty crazy. She's always out in skimpy outfits and writhing on Liam ... Sometimes he looks embarrassed for her.''

Liam and Miley were recently pictured together at the US premiere of the 22-year-old actor's latest movie 'The Hunger Games'.

And Liam recently admitted the 19-year-old beauty makes him feel ''really happy'', and he spoke out in defence of her.

He explained: ''The poor girl can't have one night where she can feel safe in her own world. It's ridiculous.''

The couple got together while filming 'The Last Song', and the Australian actor admitted romantic scenes in the motion picture helped Spark their relationship.

He said: ''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.''