The feud between Britney Spears and her sister Jamie Lynn Spears keeps growing, now that the iconic sister claims the Nickelodeon actress should take a lie detector test.

The 40-year-old artist posted a lengthy message sharing her thoughts on Jamie Lynn’s best seller book, declaring that the timing of her book release was “unbelievable,” refering to Britney’s new found freedom following the end of her 13-year conservatorship, in which she experienced difficult and traumatizing situations.

Britney went on to accuse her sister of lying, posting a video from a recent episode of ‘The Real,’ where the hosts talked about the information in Jamie’s new memoir ‘Things I Should Have Said.’

“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 !!!!” Britney continued, “My whole family including you is saying YOU DIDN’T KNOW …. Bull—it !!!”

Adrienne Bailon Houghton introduced the segment during the episode, declaring that Britney’s sister should have named her book “The Things I Should Have Said to My Sister and My Sister Alone But Instead I‘ve Decided to Make a Book for Profit.”

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The singer agreed with Adrienne, writing under her post: “What these women are saying here is pretty clear !!!!” adding, “I‘m just kinda shocked that more people like these real soul sisters aren’t telling it like it is !!!”

The host also questioned the content on Jamie Lynn’s book by saying, “If you wanna clear your name ... who is it important to clear your name to: your sister or the masses of people?”

Britney, who says her sister has continued “making money off of me,” concluded by saying she wishes Jamie Lynn “would take a lie detector test so all these masses of people see you’re lying through your teeth about me !!!!“