In the wake of the singer’s less famous singer releasing a memoir that has sold many copies, Britney took to Instagram on Friday and once again trashed Jamie Lynn for exposing family secrets.

And for flat-out lying about these secrets, according to Britney.

“National best seller ???? DUH,” Britney wrote to open her scathing message, referring to the book “Things I Should Have Said” and adding:

“The timing of your book was unbelievable Jamie Lynn … especially knowing the whole world had no clue what was really done to me !!!!

“My whole family including you is saying YOU DIDN’T KNOW …. Bullshit !!!”

Britney has been going after her younger sibling for months — first for not stepping up back when Britney was controlled by their dad via a conservatorship, and more recently for exploiting the situation by penning this biography.

“Congrats best seller … I’m not surprised at all!!!” continued Britney in her latest Instagram post.

“The nerve of you to sell a book now and talk shit but your fucking lying just like you lied about Alexa Nikolas !!!!”

(Nikolas starred with Jamie Lynn on Zoey 101 in the 2000s and wrote on Instagram, regarding the memoir: “I was pretty surprised to see her lying up a storm.”)

Britney wrote these words alongside a clip from talk show The Real in which Adrienne Bailon discusses her thoughts on the Spears’ sibling rivalry and the value of loyalty.

“If you want to clear your name, this is my thing, I’m a super family-oriented person,” Bailon says in the footage Britney wanted the world to see.

“I love my sister, my sister and I are like this [tight].

“Loyalty in my family is so important and loyalty in my sisterhood is so important.

“If you wanted to clear your name, who is it important to clear your name to? Your sister or the masses of people?”

Wrote Britney of this Real segment:

“What these women are saying here is pretty clear !!!! I’m just kinda shocked that more people like these real soul sisters aren’t telling it like it is !!!”

Concluded Britney:

I wish you would take a lie detector test so all these masses of people see you’re lying through your teeth about me !!!!

I wish the almighty, Lord would could come down and show this whole world that you’re lying and making money off of me !!!!

Britney Spears, Jamie Lynn Spears split (14 January 2022)

Jamie Lynn’s memoir includes details about alleged scandals involving the pop star, who recently called her sister a “scum person” on Twitter … and then took it back.

The author also remarks on her sister’s love life and her conservatorship battle.

Earlier this month, following numerous tense online exchanges with her sister — as Jamiie Lynn promoted her book in the press — Britney had her attorney send Jamie Lynn a cease-and-desist letter.

It claimed the publication contains “misleading or outrageous claims” about the global superstar.

“Jamie Lynn … congrats babe!

“You’ve stooped to a whole new level of LOW,” Britney tweeted on January 14, days after the Netflix actress alleged in her book that she was locked in a room with Britney, who was armed with a knife.

“I’ve never been around you ever with a knife or would I ever even think to do such!!!

“The only knife I ever saw you with at home was cutting the biggest pieces of squash I ever saw in my life and it was way too big for me to cut.”

During a recent interview with E!’s Daily Pop, Jamie Lynn said she still hope that her damaged family can rebuild.

“I can’t help the family I was born into,” she said at the time.

“I just think we’re all in a situation, and a process that we’re working through. And each of us have the right to work through that however feels best for us.”