Britney Spears calls sister Jamie Lynn 'scum' in scathing online post
The veteran pop star voiced her anger over Jamie Lynn's book, 'Things I Should Have Said'
{{#rendered}} {{/rendered}}The Spears family drama isn't dying down.
Britney Spears took to Instagram on Friday to ream out her younger sister Jamie Lynn Spears for coming out with a memoir about her family at such an "unbelievable" time.
"National best seller ???? DUH …. 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 …. Bulls--t !!! But 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 !!! Congrats best seller … I’m not surprised at all," Britney's caption begins.
{{#rendered}} {{/rendered}}The veteran pop singer went on to accuse her 30-year-old sibling of lying.
On top of the sit-down interviews, Britney and Jamie Lynn have been publicly fighting on social media. (KMazur/WireImage)
"The nerve of you to sell a book now and talk s--t but your f---ing lying just like you lied about Alexa Nikolas !!!! 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 !!!! You are scum, Jamie Lynn," Britney added.
{{#rendered}} {{/rendered}}The "Toxic" singer's post shared videos from two different talk show segments showing hosts take Britney's side.
"The Real" co-host Adrienne Houghton said she has a sister and has always cherished the bond they have. "If you wanted to clear your name who is it important to clear your name to? Your sister or the masses of people? Why did you feel the need to clear your name to millions of people who are not your family members?" Houghton asked.
Britney also shared a clip of former football pro Akbar Gbaja-Biamila speaking out about the Spears sisters' online feud, saying he doesn't it's right to "put family business out there."
{{#rendered}} {{/rendered}}Britney Spears called her little sister "scum" in a new Instagram post. (Image Group LA/Disney Channel via Getty Images)
"Will Smith came out with his book last year and what was interesting was to see how he brought everyone in that was mentioned in the book and got their approval. You can be in the same family dynamic, like with the Spears, but you can see the situation totally different…I think it could be unfair…If you didn't talk to your sister about putting all this information how you see it, that's not fair. I think that's something you resolve behind closed doors," he said.
Britney and Jamie Lynn were publicly feuding in the lead-up to the release of Jamie Lynn's memoir, "Things I Should Have Said." The book was published Jan. 18.
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Jamie Lynn Spears continued to defend herself against claims she didn't help Britney Spears end her conservatorship during a recent interview. ( Kevin Winter/Getty Images)
Jamie Lynn's series of sit-down interviews had all eyes on the sisters' social media spat as Jamie Lynn continued to spill family secrets, including details of the conservatorship. Jamie Lynn further dived into the details with Alex Cooper during Thursday's episode of the "Call Her Daddy" podcast.
Jamie Lynn said she didn't speak out against the conservatorship because she didn't think she'd be "grouped" with the people who were responsible since she'd always done "the right thing."
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"I never thought that I’d get grouped into this hatefulness because I knew that I’d always tried to help and stuff, so then I was thinking in my head, I’m never gonna have to speak up, I always did the right thing," Jamie Lynn told Cooper. "To me, it was like, why would I have to say anything? She knows it, we know it."
Jamie Lynn also revealed she was worried about legal repercussions she could face for speaking publicly.
{{#rendered}} {{/rendered}}Meanwhile, one day after the book's release, the 40-year-old pop star and her attorney Mathew Rosengart took legal action. Fox News Digital obtained a cease-and-desist letter that Rosengart sent Jamie Lynn, telling her to "cease and desist from referencing Britney derogatorily during your promotional campaign. If you fail to do so or defame her, Britney will be forced to consider and take all appropriate legal action."
Reps for Jamie Lynn did not immediately return Fox News' request for comment.