Inbetweeners stars James Buckley, Simon Bird, Blake Harrison and Joe Thomas have admitted they liked to misbehave on the set of the new film.
The actors - who rose to fame as teenage pals Jay, Will, Neil and Simon in the award-winning E4 comedy created by Damon Beesley and Iain Morris - star in the second big screen spin-off, which sees Damon and Iain make their debut as directors, which Joe likened "to two kids being left in charge of a classroom".
Simon revealed: "It was a new experience for us because Iain and Damon were directing for the first time and we took it upon ourselves, we felt it was our duty, to remind them how inexperienced they were.
Joe sniggered: "We didn't take them seriously," and James confessed: "We were patting Iain's head."
Joe chipped in: "He didn't like you patting him on the head. He did not like that. And he didn't like it when James went, 'Iain, I know we like to have a bit of a laugh but we actually think you're doing quite a good job'."
Simon added: "He found it a bit patronising..."
And Blake admitted: "They've always set up this attitude on set that if it's funny just do it, but there's normally a director in place to pull on the reins ever so slightly when things got out of control. So when Iain and Damon took over the reins, it was like the lunatics have taken over the asylum."
The first film saw the teenagers go to Malia in Crete for their last holiday before university. The Inbetweeners 2 follows them to Sydney, where Jay is living with his uncle, for a gap-year adventure.
The lads admitted filming in the Australian Outback was an incredible experience.
Joe said: "It's kind of exhilarating because it's so barren. And it would kill you if you were there on your own. We were surrounded by people taking care of us, but if that was all taken away you'd die in a day. It was extraordinary. Fifty degrees in the shade. Flies everywhere.
"The one let down about Australia, probably not really a let down, was that we didn't see any dangerous wild animals. The only animals in the Outback are flies, and they are just everywhere. They get in your eyes - they love your eyes.
"I think because everything in the outback is basically thirsty and there's water in your eyes so they're trying to get it. Which is pretty disgusting.
"But it's an amazing, amazing environment, I'd never have been anywhere like that without doing this film. It's totally barren, almost lunar. It looks incredible."
:: The Inbetweeners 2 is released in cinemas on Wednesday, August 6.