On Sunday’s episode, Perry learned the hard way that flipping your fins won’t get you too far.

As she’s done for previous Disney Nights on the show, Perry went all out with her costume, dressing up as Ariel from The Little Mermaid in a cosplay that would make any regular convention-goer proud. But in a floundering moment, the judge realized that being a mermaid is a lot harder than it looks. (Maybe she should’ve kept her feet, er, tentacles on the ground as she did with her Ursula costume back in 2019.)

As host Ryan Seacrest prepared to introduce the plan for the night’s show, a crash was suddenly heard off screen — which turned out to be Perry, who had propped her fins up on the judges’ table, and fell over backwards in her chair. Seacrest came to her rescue along with fellow judges Luke Bryan and Lionel Richie, and Perry confirmed she was okay by taking the moment in stride and waving to the audience while sipping her drink as the crowd chanted her name.

Katy Perry poses with ‘American Idol’ contestants and fellow judges Lionel Richie and Luke Bryan. ABC/RAYMOND LIU

“Hell with mermaids!” Bryan exclaimed to the camera after things got settled, while Richie added, “I love it!”

Later, Perry shared the moment on Instagram poking fun at herself by using a lyric from the movie’s well-known song “Part of Your World.”

“Flippin’ your fins you don’t get too far,” Perry wrote alongside the video from ABC. “Swipe to see what almost accidentally killed @lionelrichie.”

Despite the fall, Perry clearly enjoyed her time as a Disney princess, posting a number of behind-the-scenes photos after the show including one that showed her getting into costume — specifically, getting that mermaid tail on — with the help of an elaborate team. (And yes, the singer’s dog Nugget was also decked out as Ariel’s trusty sidekick Flounder.)

“Some BTS of a little Sunday sushi,” she joked in the caption. Among the photos she shared were images of being wheeled out on a dolly by Bryan, and posing with Bryan and Richie while joking, “I’ve never seen a human this close!”

On Monday, the popular reality-competition show will stage a special reunion episode to celebrate Idol‘s 20th anniversary, with original longtime hosts Randy Jackson and Paula Abdul returning to the judges’ table, as well as a variety of past winners and alumni including Ruben Studdard, Scotty McCreery, Jordin Sparks, David Cook, Lauren Alaina, Kris Allen, Maddie Poppe, Laine Hardy, Willie Spence, Caleb Lee Hutchinson, Grace Kinstler, and Laci Kaye Booth.

It’s sure to be another night to remember, one where Perry hopefully doesn’t flip out of her seat.