It’s hard to read the story in Billboard and not start belting out Kelly Clarkson’s “Mr. Know It All” in your head.

And in this case, the “Mr. Know It All” is Fox News host Chris Wallace.

When Wallace was on the nationally-syndicated The Mike Gallagher Show radio program on Friday (April 3), he and Gallagher had an entire conversation about fat-shaming and about Clarkson’s weight.

The final blow? Wallace saying, "She could stay off the deep dish pizza for a little while."

To me, that is an unforgivable remark. I would never get over that. (I might, as Garth Brooks once suggested, bury the hatchet -- but leave the handle sticking out.)

Wallace has since apologized.

"I sincerely apologize to Kelly Clarkson for my offensive comment. I admire her remarkable talent and that should have been the focus of any discussion about her,” he said in a statement to Us Weekly, although it’s hard to know how sincere that apology was since he was strong-armed into it after some social media backlash.

Leave it to classy Carrie Underwood to keep the focus where it belongs -- on Clarkson’s love of the music future American Idol contestants will make.

“Great to see @kelly_clarkson encouraging and passing some good words of wisdom on to these @AmericanIdol contestants! Hope they listen up,” Underwood earlier tweeted last week.