The one thing Zac Efron couldn't do while filming "Neighbors 2" in Atlanta

Zac Efron, Seth Rogen and Rose Byrne in a scene from "Neighbors 2: Sorority Rising." Photo: Justin Lubin/Universal Pictures via AP

Credit: Jennifer Brett

Credit: Jennifer Brett

Zac Efron, Seth Rogen and Rose Byrne in a scene from "Neighbors 2: Sorority Rising." Photo: Justin Lubin/Universal Pictures via AP

Zac Efron and Seth Rogen team up again for "Neighbors 2: Sorority Rising," in theaters now. The metro Atlanta-filmed comedy also stars Chloë Grace Moretz, Rose Byrne, Selena Gomez and Dave Franco. "It was really fun," Rogen said during a visit to "The Ellen Show." 

He was mortified at having to appear shirtless next to his hunky co-star in one scene - and he revealed the one thing Zac couldn't do while the movie was filming.

Photo Credit: Michael Rozman/Warner Bros.; Point Grey Pictures

Credit: Jennifer Brett

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Credit: Jennifer Brett

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"I have to be shirtless next to him and it’s horrible. It’s just horrible," Rogen lamented. "It’s basically your worst nightmare and the only moments where it’s ok is like every once in a while like on set when we’re shooting pizza will be delivered and he actually can’t eat it."

Apparently pizza isn't part of Zac's impressive fitness plan. Rogen recalled relishing a slice while Zac could only watch.

"He gets like a sad look on his face. And those are the moments where you’re like I win this round, Efron. But he’ll live 30 years longer than I will!"

Zac Efron posted this photo of himself just hanging out looking all perfect.

Credit: Jennifer Brett

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Credit: Jennifer Brett

Here's the "Neighbors 2" trailer: