Britney Spears has once again taken aim at her younger sister, Jamie Lynn, over the latter's new book.
Earlier this month, 30-year-old Jamie Lynn released her new memoir, titled Things I Should Have Said - which has since gone on to become a National Best Seller.
In the book, per news.com.au, the Zoey 101 star reportedly pleads ignorance to the struggles her sister endured throughout her highly publicized 13-year long conservatorship. According to the book's blurb, the memoir tells the story of how Jamie -Lynn became "a raw, blemished, and imperfect woman, standing in her own power."
However, older sister Britney is far from pleased about the book's release, and has ripped into her younger sibling in a scathing Instagram post shared on Friday night.
Sharing two clips from the talk shows The Real and The Talk, Britney captioned her latest Instagram post: "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 !!!!"
Of course, the release of the book came just two months after a judge decided to end the conservatorship that had controlled Britney's personal, professional and financial matters for more than 13 years.
The caption continues: "My whole family including you is saying YOU DIDN’T KNOW … Bulls**t !!! But what these women are saying [in the video] 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."
After accusing her sister of "f***ing lying", the 40-year-old 'Toxic' singer wrote: "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 concluded the post with: "You are scum, Jamie Lynn."
This certainly is not the first time the sisters have made headlines recently.
Earlier this month, Britney wrote in a now-deleted Instagram post that she should have slapped Jamie Lynn and their mom "across their f***ing faces".
After snippets of Jamie Lynn's recent sit-down interview with Good Morning America started to surface on social media, Britney wasted no time hitting back at her younger sister as she referenced her 2002 breakup with Justin Timberlake.
Alongside a photo of two cinnamon drinks, she wrote: "I flew home to Jamie Lynn on the couch watching her TV shows right after Justin and I broke up... I was a ghost there! I had worked my whole life and I didn’t know how to be served by Mamma, sit there, and get served the chocolate milkshakes with the perfectly crushed ice with the secret chunky sugar.
"Meanwhile Jamie Lynn is 12, she indulges with the TV for hours then goes to lay out on a raft at the pool. I’m in shock because this was never my life!"
In her interview with GMA, an emotional Jamie Lynn told presenter Juju Chang that although she loves her sister, things have become complicated between the two of them.