Zac Efron has revealed that his Bad Neighbours co-stars would often rib him into going topless.
The 26-year-old star, who bared his torso at the MTV Movie Awards, joked he often had no choice in the matter, especially when Seth Rogen got involved.
"I had no choice. Seth would be like, 'Dude, just take it off'. He would be like, 'Zac, take your shirt off' and (I'll say), 'OK Seth. Cool, done'," he said.
"I had to just go with the flow. It was constant. They would make me do it, just to do it."
He added: "I found out most of the time they were just s****ing with me. They didn't even need it and the camera wouldn't even be on me. They would just make me do it and laugh."
Dave Franco, Christopher Mintz-Plasse and Craig Roberts also star in Nicholas Stoller's comedy, which sees tensions rise between a fraternity house and their neighbours - a married couple with a baby, played by Seth and Rose Byrne.
"Every single day was just crazy. No matter what we were doing, it seemed like we were taking it one step too far - and then we go another step past it," Zac said.
"These guys were definitely extreme. So what you see in the movie is crazy, is actually scaled back. It was pretty intense. I can think of a lot of things (that didn't make the cut) but I don't think they're appropriate to talk about."
Zac remained tight-lipped over rumours of a romance with his co-star Halston Sage, saying: "I'm sort of (single). I can't confirm anything, I need to figure out what to say."
:: Bad Neighbours opens in cinemas on May 3.