Why Brad Pitt loved his 'Bullet Train' smart toilet and why Bad Bunny's screen wife had it easy

Brad Pitt has a love story in "Bullet Train," the comedy thriller that passed $100 million at the box office this weekend and is now out on digital.

Pitt's assassin character, Ladybug, becomes instantly enamored with the high-tech smart toilet aboard the film's Japanese high-speed train filled with lethal killers. The fully flushed idea was all Pitt's, which the star dropped just a day before shooting began on the Los Angeles train set.

"I was like, we have got to make a smart toilet," Pitt tells USA TODAY.

"That was 100% Brad," says director David Leitch, who recalls being busy on the set when an excited Pitt hurriedly approached him. "(Pitt) just kept saying 'smart toilet' and then, 'I need to be playing with a smart toilet!' And then I was like, 'Smart toilet!' and was on the phone with the art department saying we need a smart toilet here tomorrow."

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"There are beautiful gems in the script. ... And then there are beautiful gems when Brad Pitt says 'smart toilet,' " Leitch adds.

The art department hastily set up the deluxe modern toilet, and the effects teams made the system work like the real thing. That water stream is as true as a real smart toilet water stream.

"I've got to say, they rigged that up beautifully," says Pitt, who spent time riffing with the various features – water stream, air drying, toilet seat raising – before shooting scenes of Ladybug discovering the toilet treasure while seeking refuge from other assassins in the train's lavatory.

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For a physical gag, the smart toilet winds up playing a major role in "Bullet Train." Pitt was also so inspired that he came up with an anti-toilet paper line for his philosophy-spouting assassin.

"I tried to get (the line) in there, but it didn't make the movie," says Pitt, who reveals it here: 'Toilet paper is such an antiquated concept. I don't know why we're satisfied with this,' "

But seriously, Pitt loves those smart toilets. His favorite part?

"The water feature is just a gift and then the little fluff dry, I mean, what a pleasure," he says.

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Bad Bunny's screen wife Mrs. Wolf was also a major fan

Pitt's love for the smart toilet isn't the only coupling in "Bullet Train." The thriller features an actual human romance involving Bad Bunny's assassin The Wolf — told in flashback when The Wolf isn't trying to kill Brad Pitt's Ladybug on the train.

The fleeting romance scenes show The Wolf's passion for his lover who is murdered on their wedding day, which sends Mr. Wolf seeking hot revenge on the train.

Andrea Munoz, the Colombian actress who plays Mrs. Wolf, says the intense-but-short romance scenes were shot with little time to get to know Bad Bunny. They had to be separated due to strict COVID-19 shooting protocols that prevented the duo from interacting on set before cameras rolled.

"It was like 'Bring (the actors) in now, and love each other!’ says Munoz. "But it worked. We broke the ice right on camera."

The actress says it wasn't a stretch playing enamored with her famous Grammy-winning screen partner. She's a big fan of Bad Bunny's music and says he was "lovely" on the set.

"I thought he wouldn’t be approachable. But he was so sweet," says Munoz. "It was like, 'I can play being in love with this person.' That was not hard."

This article originally appeared on USA TODAY: Brad Pitt's 'Bullet Train' toilet love; Bad Bunny's screen wife talks