Jessica Simpson and John Mayer Jessica Simpson and John Mayer

Jessica Simpson — who John Mayer considers "sexual napalm" — doesn't want him kissing and telling. 

Will Jessica Simpson use Oprah to fire back at John Mayer?

"I don't want people to know how I am in bed!" she says on The Oprah Winfrey Show scheduled to air Wednesday, publicly responding for the first time to Mayer's comments in Playboy last month. Besides calling her "sexual napalm," the singer-songwriter referred to Simpson as "crack cocaine" and said she was "crazy" in bed. He later apologized and promised to "quit the sound-bite game."

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Simpson, 29, also discusses the public's criticism of her weight last year on Oprah. "You were a size 4 and people were calling you fat?" Winfrey asks the visibly upset pop star, whose reality show The Price of Beauty premieres March 15 on VH1."It's a really hard thing for me to talk about," Simpson says.