Bob Mackie is the best in the business.

The esteemed fashion designer is behind some of the world’s most iconic and historic celebrity looks, from Tina Turner’s 1978 flame dress to Madonna’s silver beaded 1991 Academy Awards gown to most of Cher’s most memorable looks.

But that doesn’t mean he’s really happy with all of his creations so far.

In his new documentary “Bob Mackie: Naked Illusion,” the client opened up about how he designed Cher’s “vulgar” look for her 1989 video “If I Could Turn Back Time,” admitting that he was is embarrassing today.

The look in question, which he refers to as a “seatbelt” outfit, was a sheer bodysuit with a thin strap that revealed the “Believe” singer’s tattooed butt.

“We dressed her in a lot of wild, sexy clothes at different times,” Mackie told Yahoo Entertainment.

“Sometimes I said, ‘You can’t wear that for long.’ The’ …an awards show or whatever, and she replied (disappointedly), “OK.” But she wanted to wear that. Bike shorts were included, but see-through bike shorts are really scary.”

The designer said he told the singer: “‘Please don’t tell anyone I designed this. Don’t let anyone know this. “I’m embarrassed,” and she was fine. Now she admits it wasn’t so good.”

The video itself also sparked a lot of controversy as it was shot aboard the battleship USS Missouri and featured hundreds of cheering sailors in the background.

The entire production was met with so much backlash that MTV banned the music video from playing until after 9 p.m

As it turns out, Cher’s stunning nude illusion dress designed by Mackie and Ray Aghayan also turned heads.

The legendary singer wore the number at the Met Gala in 1974 and on the cover of Time Magazine the following year.

According to an interview with Harper’s Bazaar, “many cities in the United States have banned this ‘shocking’ issue from newsstands,” Mackie said. “They’re still a collector’s item!”

And recently, young starlets are once again digging into the archives and picking up vintage Bob Mackie creations for eye-catching red carpet appearances.

In September, Sabrina Carpenter attended the MTV Video Music Awards in Madonna’s aforementioned silver Oscar number, obtained from Tab Vintage.

Meanwhile, Zendaya hit the red carpet for the 2024 Rock and Roll Hall of Fame induction ceremony in October and paid homage to Cher in a stunning 2001.

And Cher herself wore an edgy cutout catsuit to the documentary’s premiere in May.