Cardi B certainly got a workout during her racy performance of “WAP” at the 2021 Grammys. Alongside collaborator Megan Thee Stallion, the 28-year-old rapper writhed, twerked and crawled around the stage, clad in a custom rose gold chrome outfit by Rey Ortiz that weighed in at a “WAP”-ing 18 pounds.

“Eighteen pounds on my body,” Cardi captioned a shot of herself spread-eagled during the sexy performance. “I had to wear it tho it was amazing.”

Ortiz, who’s dressed the superstar in plenty of other eye-popping looks in the past, shared the story of how the heavy-metal getup came together on Instagram.

“We need a major metal moment for the Grammys,” the designer recalled Cardi’s stylist, Kollin Carter, telling him over the holidays. “It needs to be fully danceable, sexy and comfortable … [and] I know you can do it because you also dress drag queens.”

Ortiz called the resulting look — which required several months to complete and took Cardi’s acrobatic choreography into account — a “painful, heavy but sexy nightmare,” even though it was crafted from molded plastic instead of actual metal.

“Even 10 hours before the performance we had the task to make this monster of a project work by continuing to do last-minute modifications without compromising the design,” he revealed.

Ortiz’s efforts (not to mention Cardi’s) were clearly worth it: “WAP” went on to become one of the night’s most talked-about performances, thrilling many viewers and infuriating others.

While the X-rated track — which was recently certified 5-times platinum — might’ve seemed a shoo-in for Song and/or Record of the Year, it wasn’t snubbed; Cardi and her label are reportedly planning to submit it in 2022 as part of her next album.