Jenna Bush Hager shares grandma's brutally honest letter

Jenna Bush Hager shares the family letter Barbara Bush never wanted anyone to read.

Even grandmothers have limits–and Barbara Bush apparently reached hers during a family Tennis match.

While chatting on Today with Jenna & Sheinelle, Jenna Bush Hager looked back on a hilariously embarrassing moment that earned her a handwritten reality check from the former first lady.

Confessing she gets a little too fired up during the competition, Jenna admitted, "I'm competitive, and I like performance around competition." She then revealed she had been "doing the worm and yelling, 'Not today!'" on the tennis court.

Her father, former president George W.Bush, found the spectacle entertaining. Her grandparents? Not exactly.

"My grandfather really believed in sportsmanship, like being really kind and humble and all those things," Jenna recalled. "And I think my … behavior rubbed my grandmother the wrong way, so she wrote me a letter."

Barbara Bush did not hold back.

"That behavior on the tennis court was not becoming. And George, you shouldn't have cheered her on, either."

The best part?the legendary postscript.

"'P.S. Throw this letter away and don't tell anybody about it.'"

Safe to say, that plan did not quite workout.

Jenna also reflected on Barbara Bush’s sharp wit, recalling the former first lady’s famous exchange with The Simpsons after once calling the animated sitcom "the dumbest thing I've ever seen."

Following a playful letter from Marge Simpson, Barbara responded with an apology, quipping, "I foolishly didn't know you had one," before ending with another memorable line: "Homer looks like a handsome fella!"

Decades later, Barbara Bush’s humour–and honesty–are still stealing the show.