Pratt said he's "certain" that he and co-star Bryce Dallas Howard were swimming in urine while filming the dinosaur-stuffed sequel.
"Boy I tell you, they put a lot of chlorine in the water," Pratt said on Friday night. "Because you've got a crew of about 85 people just pissing in this pool... We didn't have time for people to pee."
"So you knew people were peeing?" Newton ask, also revealing a hilarious "pee face."
"I'm certain," Pratt replied. "Well I mean, you're not supposed to pee in the pool, but no one got out. And I know because I had to be underwater with my eyes open ... as if I could see with my eyes open under water."
The "Westworld" star then asked Pratt if he relieved himself in the water. "I actually shit myself," he replied. "Time is money on a movie like this."
Norton asked Howard if she peed in the pool. The actress was embarrassed, so Pratt helped her out saying, "You didn't pee, Claire [her character] peed."
"Every time you've said that for the last like seven months," Howard said. "I'm just so deeply ashamed."
But pee wasn't the only topic on the British talk show, they also discussed pubic wigs. Being on an HBO show like "Westworld," nudity is an every day occurrence. Newton was offered to wear a merkin -- a pubic hair wig -- on set, but declined because she doesn't need it.
"I did say no to my merkin," the actress said. "Well, number one, to be honest, one of the reasons why they provided them is that a lot of women do things to alter what's going on down there," adding "I didn't need the merkin because I don't alter anything – [I have a] full 70s bush."
Being the funny man we know and love, Pratt had to give his two-cents to the debate. "I know that it's probably has something to do with historical accuracy," he said. "You're not as prudish as we are in the States, but there's something about a rating too right?"
"You can see a bush, but if you see one with no bush then it's somehow more salacious and can't pass the rating thing," said Newton.
"I'm pro-bush, okay," he admitted, giving her a congratulatory fist bump.
Like many movie stars, Goldblum, Newton, and Howard all get mistaken for other people, or more often, fans think that they look like them. Goldblum said when it happens to him, he says that he's "flattered" and will often reply with: "I wish I looked like you."
One of the most popular pair of celebrity dopplegangers is Howard and her fellow "The Help" star Jessica Chastain. They could be long-lost sisters.
"It's like really, really, really true, like it's very flattering to me," Howard said about being mistaken for Chastain. "She's unbelievable."
Both red-headed beauties attended college in New York City -- with Howard attending NYU and Chastain, Julliard. Howard said that she was even getting mistaken for Chastain before they were even famous.
"There were many times," she began. "First time it happened, I went into a Starbucks where people would mistake me for a girl named Jess," admitting that the barista was "certain" that they were the same person.
Newton, on the other hand, often gets mistaken for Pratt's other female co-star Zoe Saldana. The actress explained that friend Victoria Beckham was "mortified" when she accidentally mistook Newton for Saldana during a SoulCycle class. Don't worry, Posh. It happens.
"Jurassic World: Fallen Kingdom" hits theaters June 22nd and catch "Westworld" every Sunday on HBO.