James Corden wears shapewear under his suits

James Corden and his wife Julia Carey

James Corden has admitted he wears Spanx shapewear under his suits.

During a chat about the ways fashion can cause pain with Rachel Brosnahan and RuPaul Charles for The Late Late Show with James Corden on Monday night, the host revealed that he wears tight undergarments while presenting the talk show.

"I think I'm making a sacrifice wearing these Spanx. I'm not even joking," he laughed. "My New Year's resolution is to try and get to a point where I do one show this year not wearing Spanx. It'll be like I'm suddenly free, Ru! I won't know what to do! I'll be breathing."

RuPaul responded, "Will we know it? Will we know it when you're not wearing..." to which Rachel smiled, "We'll know."

Accordingly, James insisted that he will make a public announcement when he no longer needs Spanx.

"Oh, you'll know, babe. You'll know, babe," the 41-year-old quipped. "I will shout it from the rooftops! It'll be my first-ever Instagram Story."

The topic of tight clothing first came up during the conversation when Rachel admitted she has suffered a "corset-related injury" from the '50s-era costumes she wears to play stand-up comedienne Miriam 'Midge' Maisel on hit TV show The Marvelous Mrs. Maisel.

"We talk so fast on the show that to get all the words out you can't really take very many breaths," the actress explained. "And I think I wasn't breathing a lot and I was a bit constrained and apparently some of my ribs are sort of fused together."

But while Rachel can't take "super deep breaths anymore," she insisted that her ailment is a "Champagne problem".

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