Britney Spears has brought an unlikely player into her ongoing family feud.
Taking to Instagram with another fiery rant about her little sister this week, the singer sensationally claimed she "should have slapped" Jamie Lynn and her mother when she had the chance.
But while the singer removed the post shortly after sharing it, she re-posted it today with some additions — pulling Christina Aguilera's name into the mess and slamming her sister for "dying her hair" like the fellow 90s pop sensation when she was younger.
Spears and Aguilera were regularly pitted against each other during the early 2000s, with their feud intensifying after their infamous 2003 MTV Video Music Awards performance with Madonna.
It comes as Jamie Lynn Spears continues to go public with her own experiences during her childhood and throughout Britney's lengthy conservatorship battle while promoting her new book Things I Should Have Said.
Last week, Jamie Lynn alleged on US show Nightline that Britney once locked the pair of them in a room together while holding a knife, before describing her sister's past behaviour as "erratic, paranoid and spiralling" during an interview on Good Morning America.
On Tuesday, the actor also broke down in tears on the Call Her Daddy podcast, saying she felt unseen because of who her sister is, a confession which earned the ire of Britney.
"I didn't get to cry," the pop icon, 39, wrote in response on Instagram. "I had to be strong … TOO STRONG !!!"
On Wednesday, Britney went one further with a lengthy Instagram tirade beneath an image of two chocolate milkshakes, sharing her memories from a time she returned home to her family shortly after splitting from Justin Timberlake.
Writing that she felt like she "didn't know how to be served" by her mum after she'd "worked her whole life", Britney expressed shock over how cruisy Jamie Lynn's lifestyle seemed in comparison, despite the then-12-year-old also finding fame as the star of Nickelodeon's Zoey 101.
"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!!!!," Britney recalled of the trip home.
"Jamie Lynn had a new Nickelodeon show … All I remember saying was "DAMN !!! How the hell does a 12-year-old land a Nickelodeon show ????" … HMMMMMMMM … Well I never got my iced chocolate drink !!! I mean yeah … I'm grown up right ??? But then maybe I might need a little support," she wrote, referring to her mother Lynne.
Britney went on to refer to a People Magazine cover, before claiming Lynne was "on pain medication and could barely hold a conversation".
"I'm sorry Jamie Lynn, I wasn't strong enough to do what should have been done … slapped you and Mamma right across your f***ing faces!!!!!," Britney's post ended.
Today, she added: "When I came home and your little friends all thought I wasn't cool... You felt bad for me in the breakup... HELL NO you didn't !!! You and your friends all dued your hair like Christina Aguilera and you no longer would play with me anymore !!!
"I get it, you were 12 but you were f***ing hateful to Mamma being cool with your stupid dark hair."
The Spears sisters have been publicly sparring for weeks as Jamie Lynn promotes her new memoir.
Following the Sweet Magnolia star's first interview on Good Morning America, Britney called her "scum," and tweeted, "My family ruined my dreams 100 billion per cent and [tried] to make me look like the crazy one."
Jamie Lynn then begged to end their public feud on social media, writing, "I have attempted many times to speak to you directly and handle this privately like sisters should, but you still choose to do everything on a public platform."
However, the former child star continued to discuss the feud while promoting her book on Call Her Daddy.