How the 'Vacation' Reboot Cast Chris Hemsworth's Huge Prosthetic Penis

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“Oh no, it's real.”

John Francis Daley and Jonathan M. Goldstein, the writers and directors of the Vacation reboot,were quick to correct us when we brought up the most important cinematic contribution of our generation: Chris Hemsworth’s prosthetic penis.

“He is an ugly man,” Goldstein joked to ETonline. “He is hard to look at so you find yourself averting your eyes a lot.”

“We had no idea what we were getting into with him and we had no idea he was going to be so good in that role,” Daley added. “We didn't know how he would play it, if he would try to play up the comedy too much, try too hard. He knew exactly the tone we were going for and he embodied that role so well it was amazing to watch.”

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Warner Bros. Pictures

OK, but back to the penis. It’s not actually Hemsworth’s erection onscreen. In fact, it sounds like it was quite the process to pick out his prosthetic. You know how people say size doesn’t matter? That’s a lie.

Goldstein: “First we had to make a model based on my own.”

Daley: “Then we added about 8 inches to it. We had a choice between an 8-inch and a 10-inch, and we tried them both on him in a room above the bedroom we were shooting. Just the three of us alone in a room sampling penises was a very strange experience for us.”

Goldstein: “Strange and heady.”

Daley: “No pun intended.”

In the end, it was worth the effort, as it’s one of the funniest and raunchiest gags in the all-around hilarious and very, very raunchy film. It seems like it would have been impossible to keep a straight face while shooting opposite him though.

“Guess what? I didn't. I laughed the whole time,” Ed Helms, who plays Rusty Griswold all grown up, admitted. “Thankfully I was off camera for almost all of it...I hope we see him do a lot more comedy. He has got a serious funny bone. No pun intended. That got dirty.”

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Warner Bros. Pictures

Meanwhile, co-star Christina Applegate recalled how seriously Hemsworth took his fake penis on set. “That scene would not have worked without him being as amazing as he was in it,” she said.

“It could have been vulgar," she continued. "Someone would have messed that up, because they would be thinking, ‘This is so funny what I am doing with my thing, and I am going to be really, super funny with it.’ He wasn't. He was playing it as if he was fully clothed.”

Anyway, Applegate says she was focused on a different body part.

“The rest of the time, we all just spent talking about his abs,” she said. “Not in a lascivious way. Just in like how, that's not... I have never seen..." Clearly she is still speechless.

We suggested Hemsworth seems to have a six-pack and then another six-pack on top of it. “And then some on the back,” Applegate agreed. “And the skin quality looks like-- Come on, that looks so soft. What moisturizer do you use, that's incredible. We all would watch and be like, ‘Mhm. Amazing. Wow.’ Men, women, children, animals, everyone stopped.”

Not lascivious, huh? Not that we can blame her. Vacation hits theaters July 29.

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