George Clooney hasn't forgiven Russell Crowe for calling him a "sell out".
The 'Gravity' star fell out with the 'Gladiator' actor in 2005, after he slated him in an interview with GQ magazine.
The silver-haired actor was slammed by Russell, 49, for modelling suits in an advertising campaign, and then shortly afterwards George was sent a poetry book by way of apology - something he didn't accept.
The 52-year-old actor told the new issue of Esquire magazine: "The truth is that [Russell Crowe] did send me a book of poems to apologise for insulting the s**t out of me, which he did.
"And that's when he really went off on me. 'Who the f*** does this guy think he is? He's a Frank Sinatra wannabe.' He really went after me."
Knowing that he might run into George during awards season later on, Russell then attempted to apologise for his actions.
George said: "I think he said, 'I was misquoted,' and I was like, 'Yeah, yeah. Whatever.' "
George also spoke candidly about Leonardo DiCaprio and how the pair played a basketball game together after striking up a friendship.
Leo's over-bearing friends talked a good game before the match, but George's team ran out easy winners - leading him to contemplate whether Leonardo, 39, has enough honesty in his life.
George said: "The discrepancy between their game and how they talked about their game made me think of how important it is to have someone in your life to tell you what's what. I'm not sure if Leo has someone like that."
Meanwhile, Clooney also opened up on his love for pranking his co-stars, by making them think they've got fat.
The 'Gravity' actor is known for his practical jokes and says one of his favourite pranks involves sending his actor friends into a panicked dieting frenzy by having their clothes altered so they no longer fit.
He told the New York Post newspaper: "I do enjoy whenever an actor's trying to lose weight having the wardrobe people take in their clothes.
"It just makes me laugh, watching them eating, like, a grape the next day. And they do it for weeks. It's good fun."
George was speaking ahead of receiving the Stanley Kubrick Britannia Award for Excellence in Film at the BAFTA Los Angeles Awards over the weekend and warned his friend and 'Ocean's 12' co-star, Julia Roberts - who presented him with the prize - to be careful with her speech as, he will be returning the favour when he hands out awards in the coming 2014 season.
He joked: "I will take her down. She has to walk a little on eggshells with me right now."
George's confession of his wardrobe prank will come as a relief to Matt Damon, as the 'Bourne Identity' star has previously admitted he was unsure whether he had been a victim of his friend's sense of humour.
He previously said: "A couple of years ago I hadn't been working out and I'd got kind of fat. I had to go to a function and when I tried on my suit, it was too tight.
"My immediate thought was that my buddy George Clooney had hired someone to get into my closet and cut down my clothes. I seriously thought that - until my wife said, very gently, 'Do you think it might be that you've put on some weight?' "