Uh oh! Liam Hemsworth gets testy when he thinks a reporter called him by his brother's name

Warning! Be careful what you say around Liam Hemsworth. Uttering the C-word could get you into trouble.

Check out the video above to see the 25-year-old Hunger Games star's reaction when he thought an interviewer at Comic Con called him by his 31-year-old brother Chris' name.

We're glad for the reporter's sake that he had an excellent excuse. Clearly Liam has a few big brother issues to sort out.