Liam Hemsworth became angry when he mistakenly thought a reporter called him Chris.
The 25-year-old actor - whose older brother Chris, 31, stars as Thor in the Marvel series - became visibly annoyed with a reporter after thinking he mistook him for his sibling.
As Liam walked along the red carpet at Comic-Con in San Diego, the reporter said: "Hi I'm Chris, it's nice to meet you."
But Liam replied: "You called me Chris? It's Liam. You called me Chris didn't you?"
However, the reporter was quick to defend himself, saying: "Oh no, I said I'm Chris."
At which point Liam backed down and said: "Oh, you're Chris. Phew.